Reducing the impact of chemical contamination of sensors.

Dust, humidity, corrosive media and chemical contamination can impair the measurement performance of industrial sensors. Depending on the application, these stresses affect different sensor areas and can cause measurement drift or increase maintenance requirements. E+E Elektronik addresses these challenges with application-specific protection concepts for sensor elements, connections and other sensitive areas. With ChemShield, E+E Elektronik is now adding a protective barrier specifically developed for chemically demanding applications.

E+E Shield Technologies

The protection concepts from E+E Elektronik act where environmental conditions can affect sensor performance. Each technology fulfils a different function.

SensShield is a protective coating for the sensor element as well as its connections and solder joints. It reduces the impact of dust, dirt, oily contamination, salts, humidity and corrosive exposure. At the same time, the coating helps prevent stray impedances caused by deposits on the sensor surface or connection leads.

LeadsShield protects particularly sensitive sensor connections and solder joints through targeted encapsulation. Only the sensor element itself comes into contact with the medium being measured. This protects critical connection areas from corrosion and contamination without unnecessarily affecting the sensor's response characteristics.

ChemShield adds a barrier against chemical contamination to these protection concepts. The coating is applied to defined areas such as the sensor element and solder joints. It reduces the impact of harmful chemical substances and supports long-term stable measurement performance in chemically demanding environments.

Contaminated Sensor

For chemically demanding processes.
Chemical exposure places particularly high demands on the sensor element in humidity measurement. Process media can change, oils age or oxidise, and residues from production and cleaning processes can affect sensitive sensor areas. This can lead to measurement drift and reduced long-term stability.

ChemShield forms an additional barrier against these influences. This extends the application range of selected E+E Elektronik humidity and moisture in oil sensors to environments with increased chemical exposure.

Long-term stable moisture measurement in oil.
One key area of application is moisture measurement in oil. Ageing, oxidation and contamination can change the chemical properties of an oil and place additional stress on the sensor element. ChemShield reduces the impact of these changes and supports long-term stable moisture measurement.

The technology is used, among other products, in the EE360 and EE364 moisture in oil sensors. Depending on the application and product configuration, this also makes them suitable for demanding lubricating, hydraulic and insulating oils as well as selected natural ester oils. ChemShield also provides additional protection against chemical exposure in contaminated turbine, compressor and hydraulic oils.

Enhanced protection for industrial humidity applications.
In industrial humidity measurement, chemical contaminants can also affect sensor performance. Typical applications include test and climate chambers, fume cupboards, pharmaceutical environments with intensive cleaning, biofilters, fertiliser environments, and specialised drying and fermentation processes.

For selected applications, E+E Elektronik combines ChemShield with SensShield. In the EE310 humidity and temperature sensor, this combination supports long-term stable measurement performance even under increased chemical exposure. The specific configuration is matched to the respective process conditions.

Protection matched to the measurement task.
E+E Elektronik does not take a one-size-fits-all approach to sensor protection. What matters is which components are exposed to which stresses in the respective application. SensShield, LeadsShield and ChemShield can therefore be used selectively and combined as required.

This allows the level of protection, measurement performance, response characteristics and serviceability to be matched to the specific application. The goal is reliable, long-term stable measurements even under demanding industrial conditions.

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Hardy digital humidity and temperature sensors.

Two digital humidity and temperature sensors are now available through Sensirion's global distribution network. The the SHT40-AD1P-R2 and SHT41-AD1P-R2 Sensors, designed for demanding environments, deliver high accuracy and reliability and are equipped with a removable protective cover to ensure durability during handling and deployment.

They are the latest additions to Sensirion’s well known family of digital humidity and temperature sensors. They are engineered to provide accurate measurements, with the SHT40-AD1P-R2 offering ±1.8% RH (max. ±3.5%) and ±0.2°C, and the SHT41-AD1P-R2 delivering ±1.8% RH (max. ±2.5%) and ±0.2°C accuracy. Built with a compact DFN housing, the sensors are ideal for space-constrained applications and can easily be integrated into a wide range of devices and systems thanks to their standard I2C interface and fixed 0x45 I2C address.

The removable protective cover is a key feature, offering additional protection during both handling and deployment, ensuring they perform reliably even in high-volume production environments. Whether used in industrial systems, HVAC equipment, or consumer products, these sensors combine durability, ease of integration, and high-precision measurement for a variety of applications.

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Minor investments in sensor quality protect major assets.

Sensor specification is an important consideration when choosing process monitoring and control equipment. However, in the following article, Juhani Lehto from Vaisala explains why the quality of a sensor can be difficult to determine from a spec sheet alone.

The cost of high-end sensors can be negligible in comparison with the processes and assets that they help to manage and protect. Process managers should therefore invest in measurement technologies that have been proven to deliver stable, accurate reliable measurements in the long-term.

Sensor selection.
The suitability of a sensor for a specific application can be determined by a quick examination of its datasheet. For example, the sensor will need to operate within a known range of temperature and pressure, it will provide an acceptable output signal and it will deliver measurements within a claimed level of accuracy and precision. However, there are several important factors to consider when choosing sensors. Beyond accuracy, these include stability, reliability, and any variance in performance due to process or environmental conditions.

Stability is perhaps the most important criterion because sensors must be accurate and reliable even in demanding environments, following installation and in the long-term. The specifications of different sensor suppliers may state similar accuracies, but this does not provide insights or verification of sensor accuracy after one year, or several years. All sensors drift, but some drift more than others, and some drift more quickly, while others have good stability with minimal drifting, maintaining measurement accuracy for years. Therefore, the stability of sensors should be the most important factor to consider because it influences performance and costs over a long time and is reflected in calibration and maintenance requirements.

Given the potential costs of long-term unreliability, it is important to consider the lifetime cost of sensors, and not just their purchase cost.

In addition to good stability, high-quality instruments are also easy to maintain, calibrate, adjust, and fine-tune, which lowers lifetime costs and is good news for operation and maintenance staff. Having convenient tools for verifying and maintaining the sensors and transmitters enhances reliability and provides peace of mind throughout the life of the instrumentation.

The cost of inaccuracy can be large.
Cooling represents a high proportion of the costs and carbon footprint of running a datacentre. Vaisala participated in a datacentre trial to simulate how much more energy would be used if there was just one-degree of temperature measurement error, causing excessive cooling. The results showed that this one-degree of error increased energy consumption by more than 8.5%. Given the size of modern datacentres and assuming the same deviation can take place over a decade, this seemingly tiny error translates into many millions of euros of extra costs, particularly if server uptime is affected.

Vaisala Echo measurement infrastructure brings enterprise muscle to SMEs Traditionally only large corporations have had the resources to build measurement infrastructures with advanced features such as remote monitoring, firmware updates and easy scalability. Vaisala Echo connects Vaisala measurement devices and monitoring software to create an intelligent measurement infrastructure, without the requirement, and cost, of developing a bespoke solution.

In practice, customers will not need to buy Echo separately, because it is a built-in feature for Echo-compatible Vaisala measurement products. Simple to set up and run, Echo provides reliable, always-on access to data and alerts from all compatible devices, with remote firmware updates for all connected devices.

A major benefit of Echo is easy access to comprehensive reporting – both current and historic. Echo reports current conditions in real-time and enables notifications/alerts, and all data is encrypted in transit and rest, and secured with digital certificates.

Case study: sausage casings.
A team of British process engineers has developed a technique for manufacturing collagen sausage casings which protects product quality and trebles output. The process relies on precise monitoring of temperature and humidity with Vaisala sensors, combined with multi-stage feedback control.

The manufacture of collagen sausage skins from animal hide is a good example of sustainable production because it recycles a waste product into a valuable commodity that helps to improve the quality and consistency of sausages. However, all sausage casings are delicate and require precise conditions and careful handling during manufacture, storage and distribution, and throughout the subsequent sausage manufacturing process.

Natural casings from the small intestine of meat animals tend to be variable in length, diameter and thickness, so they are not ideal for high-speed sausage manufacturing processes. In contrast, collagen casings offer reliable, consistent features, and are therefore ideal for fast, efficient processes. Also, collagen casings do not need to be stored in chilled conditions and have a longer shelf-life than traditional casings. However, sausage casings are delicate, so precise management of handling processes and environmental conditions is essential.

Collagen casings are ready to use straight out of the package, horn loading is quick and easy, and there is no requirement for soaking and untangling of bundles. In comparison with sausages in natural casings, there are no seasonal variations, and sausages manufactured in collagen casings offer improved cooking coverage which delivers a superior cooked appearance

Prior to the development of a new product handling system, the sausage skin manufacturer utilised a conveyorised flat sheet collagen dryer, but this created friction that could lead to ripping and product wastage. The process was slow and wasteful, so the engineers were challenged to develop a new, less damaging technique for drying and processing the extruded cylindrical collagen cases. A key feature of the new process would be to minimise friction and optimise both temperature and humidity, irrespective of the plant’s geographical location.

The new processing solution allows the casings to be inflated with hot, dehumidified process air provided by a silica-based desiccant rotor. New equipment was also developed for transporting the inflated gel using an innovative handling system.

HMT120

The new system employs three precision sensors. A Vaisala HMT120 humidity transmitter monitors environmental humidity, so that dry air can be recirculated when outside conditions are too humid. In addition, two Vaisala DMP5 dewpoint transmitters monitor process air to ensure that the collagen products are maintained in ideal conditions by a multi-stage feedback control system.

The HMT120 transmitter contains Vaisala’s HUMICAP® technology; a thin-film polymer-based capacitive humidity sensor, which delivers accuracy, reliability, long-term stability and is insensitive to condensation or contamination.

The DMP5 dewpoint transmitters incorporate the Vaisala DRYCAP® sensor, which is also designed for accuracy, reliability and stability. The sensor is condensation-resistant and is immune to contamination, however, the high level of performance delivered by this technology is based on a capacitive thin-film polymer sensor and an autocalibration function. The sensor also has a rapid response time and fast recovery after wetting.

Case study: baking ovens.
Climate change, environmental concerns and rising energy prices are driving demand for improved efficiency across all industries; not least in food production where processes involving baking ovens can run at temperatures of up to 325°C. Bühler’s latest indirect-fired convection ovens, therefore aim to increase efficiency in line with the company’s strategic commitment to help customers make substantial savings in energy, water, and product wastage.

By monitoring humidity levels accurately inside an oven, it is possible control the process to maintain a consistent baking profile, even with fluctuations in ambient conditions or ingredient quality. This enables a more consistent product in terms of spread, thickness, colouring, and other important indicators of quality. This improved consistency also helps to minimise wastage.

Ovens with built-in measurement technology enable process managers to control the humidity and temperature of their ovens more effectively, which can be particularly valuable for those producing multiple products with different baking profiles.

Summary.
The applications highlighted above demonstrate the critically important role of accurate stable measurements, which highlights the need to invest in proven, high-quality sensors, particularly when the costs of not doing so can be so great.

In datacentres accurate temperature measurement can save enormous energy costs, in baking ovens accurate sensors can improve product quality, save energy and reduce wastage, and in sausage skin manufacture accurate sensors save time, reduce waste and increase productivity three-fold.

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Why should dew point sensors have a fast response?

Humidity is the enemy of battery manufacturers, so its measurement and control is extremely important – not just for the plant’s energy efficiency, but also for the quality and yield of batteries, affecting issues such as range in EVs. One of Vaisala’s experts Antti Viitanen explains why a fast response time is so important for dew point sensors.

Humidity control is obviously critical to ensuring battery quality and preventing defects. Battery manufacturers use dehumidifier units (DHU) to ensure that the air circulating in the process meets strict specifications. In battery production, humidity levels need to be kept extremely low, which means that a lot of dry air is needed, and drying requires heat and, therefore, energy. One of the most important ways to optimize energy usage is to measure dew point and temperature and use these parameters to control the DHU.

Antti Viitanen is a Product Manager at Vaisala for Industrial Instruments and is mainly focusing on OEM products/Dew Point and Carbon Dioxide products. He has over 15 years of experience in electronic sensor technology. Antti holds a Master of Science degree in Electrical Engineering from Aalto University, Finland.

The amount of heating required changes as the outside humidity changes. On wet days more heat is needed and on dry days less, but the air fed into the manufacturing spaces must be consistently dry. So how can the dryness of the air blown in by the DHUs be kept at exactly the right level without wasting energy?

Accuracy and speed are essential.
In battery manufacturing the sensors used to measure humidity must be extremely accurate: At a dew point of around -70 °C, there will only be 2.6 molecules of water in a million particles of air.

Speed is also of the essence. The rotating drums inside DHUs consist of two main parts:

• the drying section made of desiccant material that draws the moisture out of the air
• the regeneration section that drives heated air in the opposite direction to take moisture away from the desiccant material

The segments typically rotate once every ten minutes or so. If the moisture level of the incoming air is above the set limit, more heat is needed to remove the water molecules; if the moisture level is below the set limit, less heat is needed. The sensor technology must be able measure the changes in humidity within the ten-minute window or the opportunity to adjust the heating for that rotation will have been missed. To get around this challenge, sensors that are too slow to detect such changes in time typically average out results across multiple readings. The problem with this approach is that drying cannot be controlled in real time. Lack of control over drying leads to unstable humidity conditions, increased safety risks, and potential negative impacts on product quality.

Fast response time enables real-time control.
The ability to measure humidity variations within one drum rotation, and not just between rotations, is a vitally important feature of dew point sensors in battery manufacture. With this capability it is possible to control the process in real-time to maintain optimal dryness levels in each stage of production and to prevent product defects.

Sensor response times are slower when air is dryer, and faster at higher humidity levels. The extreme dryness required in the DHUs of battery plants makes it challenging to measure fast enough, which means that operators risk relying on falsely high humidity readings. In turn, this could lead to over-drying of the air and wasting a lot of energy. Vaisala claims that its dew point sensors have a response speed up to many times faster than competing products. Accurate, fast-response sensors therefore help to optimize the efficiency of DHUs so that they only dry air as much as is necessary. This lowers both energy consumption and operational costs.

The ability to measure in real-time over a single rotation enables better control of humidity and costs. However, a further benefit can be achieved by comparing accurate data from each cycle, to identify small anomalies before they escalate into bigger problems. This supports predictive maintenance and condition-based maintenance, both of which further reduce operating costs – as well as the headaches caused by potential product quality issues.

In addition to the accuracy and fast response of a dew point sensor, low drift and long-term reliability are also essential features of sensors in environments like battery manufacturing where sensor failure could compromise production quality and safety, affecting issues such as charging speed and range in EVs for example.

In summary, an investment in accurate, reliable, fast-response sensors would be negligible in comparison with the cost savings and other benefits that it would deliver. In addition, at Vaisala we firmly believe that a compromise on sensor quality would not be worth the risks associated with the potential effects on battery yield and quality.

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Removing greenwashing from carbon capture.

Vaisala has launched a new measurement product, MGP241, that measures CO₂ and humidity and is specifically designed to bring transparency to CCUS projects. Both governments and private companies need CCUS to reduce and offset carbon emissions if they are to meet their reported decarbonization targets. However, with current technology still not ready for widespread use, constant, and accurate measurement of captured carbon is vital to ensure its continued development.

Carbon capture, utilization and storage, or CCUS, is a field that has sparked a lot of public debate – and investments. Knowing exactly how much and what quality carbon has been captured is essential if CCUS is to become a viable addition to the toolset against climate change. Vaisala’s new MGP241 multigas probe offers always-on data at a third of the cost compared to measurement solutions most used in CCUS processes today.

“No one knows yet if CCUS will indeed grow to be a significant solution in our fight against climate change. The technology is still in its early stages. What we can solve now is how to make measuring these projects as transparent and efficient as possible to leave no room for guesswork or sugarcoating the results – our numbers don’t lie,” says Julia Salovaara, Strategy and Business Development Manager at Vaisala.

Critical industries depend on CCUS.
CCUS has already seen some major investments. According to BloombergNEF, a record $6.4 billion was invested into CCUS technology in 2022, more than doubling from the year before and with the U.S. leading the way with 45% of the total investments. Yet, many projects are behind schedule or not producing their promised results.

The success of CCUS technology is especially critical for hard-to-abate industries like materials manufacturing, energy production, and the chemical industry. With high emissions and few other significant solutions beyond improving their energy efficiency, these industries experience increased pressures from regulators and the public to decarbonize their operations.

One especially crucial industry is the cement industry that alone emits 7% of global CO₂. Additionally, the global demand for cement is expected to increase 12–23% by 2050. One of the early success stories, Carbonaide, helps the cement industry utilize captured carbon dioxide in concrete manufacturing.

Through the carbonization process, Carbonaide’s technology reduces the amount of cement needed in concrete production. While the reduction of cement needed is remarkable, 20–100%, the process also creates a permanent storage for the carbon captured from an emission source.

Carbonaide partnered with Vaisala from the start to make sure they know exactly what is happening in each step of the process and, eventually, how much carbon is stored.

“Globally, Carbonaide's technology has the potential to store 500 megatons of CO₂ annually by 2050 in precast concrete products – roughly the same annual emissions of France and the UK combined. The investment case we offer our customers is entirely based on accurate measurements and transparency. With Vaisala, we can trust that the numbers we share with our partners are correct,” says Jonne Hirvonen, Chief Operating Officer at Carbonaide.

Transparent measuring at a significantly lower cost.
MPG241 measures carbon dioxide and humidity in point source and direct air carbon capture processes, and in different carbon utilization and storage projects.

Julia Salovaara

Unlike traditional gas analyzers, Vaisala’s MGP241 requires no expensive calibration gases, needs dramatically less maintenance, and promises a 10+ year lifespan in heavy-duty use. The compact size and in-situ design of the instrument has allowed for competitive pricing – around a third of the price of most common solutions in the market.

“Our new probe measures directly in the gas flow and shows test results in real time. This level of transparency and proof is essential for process optimization, building trust with stakeholders, and demonstrating genuine commitment to sustainability,” added Julia Salovaara.

The MGP241 is be available now. 

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Datacentre sustainability.

A novel sensor system has been developed to help datacentres optimise the energy efficiency and sustainability of their operations.

Anu Kätkä from Vaisala (right) describes the development of a modular daisy-chain temperature/humidity sensor configuration, which has dramatically reduced cabling requirements and lowered the carbon footprint of building management systems (BMS).

Background.
The global demand for datacentres is being driven by cloud-based services, AI, automation and digitisation. These data handling facilities house large amounts of IT infrastructure and require high levels of power to run the equipment and to cool it. The latest servers are more energy efficient and able to operate at higher temperatures. As major consumers of power and land, data centre operators have an undeniable responsibility to aggressively reduce emissions and lessen environmental impacts wherever possible. In addition, datacentres frequently contain critically important data, and it is not uncommon for 99.999% uptime to be a requirement. The monitoring and control requirements are therefore comprehensive and stringent.

Partners in innovation.
Vantage Data Centres powers, cools, protects and connects the technology of the world’s well-known hyperscalers, cloud providers and large enterprises. Developing and operating across five continents in North America, EMEA and Asia Pacific, Vantage has evolved data centre design in innovative ways to deliver dramatic gains in reliability, efficiency and sustainability in flexible environments that can scale as quickly as the market demands.

Vaisala’s development project was initially prompted by the sustainability requirements of the new Vantage campuses. “We are constantly looking for ways to improve both the efficiency and sustainability of our datacentres,” explains Eugenio Lukianov, Principal Automation Manager, EMEA, Vantage Data centres. “Due to their accuracy and reliability, Vaisala sensors are frequently specified in the requirements of our new or refurbished datacentres worldwide. Many of our facilities are large, and the sensor cabling requirement can be enormous, so we were keen to find a better solution.” 

Engineers from Vaisala and Vantage found that the amount of cabling required at datacentres could be significantly reduced if the sensors could be re-designed to be daisy-chained, rather than each having their own individual cable. A sensor development project therefore progressed with this as its key objective, but additional benefits were also realised by the new sensor solution. “In order to facilitate the daisy-chain, it was necessary for the sensors to be ‘plug and play’ which made installation so much easier,” Eugenio says. “The sensor cables are initially coiled in the roof space, and then, once the servers are installed, the sensors are simply dropped into place. This modular approach also simplifies ongoing maintenance because any damaged sensors or cables can be quickly and easily swapped out.”

The cable reduction potential of the daisy-chain solution is very significant. For example, a single 100m datacentre aisle, with 30 instruments at 3m spacing, each with a dedicated cable and a 3m cable drop would require about 1695 metres of cable, which is more than a mile of cable! In contrast, if the same aisle is equipped with the daisy-chain solution, the cabling drops to just 187 metres, representing an 89% drop in carbon footprint.

Environmental measurements at Vantage Data Centres.
One of the key measures of sustainability at datacentres is power usage effectiveness (PUE), which is derived by dividing total power consumption by the power used to operate the IT equipment. So, the more efficient the datacentre, the lower the PUE, and Eugenio says: “This is an important metric for us - we continuously create downward pressure on this figure with accurate measurements and tight control of the cooling operations.”

The sensor daisy-chains at Vantage transmit data to the Vantage servers, and the ongoing accuracy of the measurements is essential for the efficiency of cooling. Vaisala sensors are also deployed outside the building, so that outdoor air can be utilised by economisation to reduce the energy required for cooling and thereby lower the PUE.

In addition to the critical areas of the Vantage datacentres, Vaisala sensors are also located in non-critical rooms such as storage areas and offices, providing data for normal HVAC control.

At Vaisala, we believe that by specifying our measurement technologies, datacentre customers can ensure that the efficiency of their cooling operations is underpinned by accurate data. However, at Vantage, Eugenio believes that the benefits extend beyond long-term accuracy and energy efficiency. “The modularity of the daisy-chain saves time and money during installation and maintenance, and with our partners and system integrators utilising Vaisala technology, we have been able to reduce the volume of spares and training that are required.”

The daisy chain systems have now been installed for up to two years in British campuses, and Eugenio says: “We are very pleased with the way that Vaisala responded to our request, working collaboratively with us to develop the daisy-chain solution.” Reflecting on performance to-date, he adds: “So far, the accuracy has been very good and there have been no complaints from our operational teams.”

Looking forward, Eugenio says: “The number of organisations looking to use datacentres is constantly expanding, and all of them want to secure a minimum 5-year capacity, so the sector is set for even more growth. We will therefore ensure that more sites benefit from the sensor daisy-chain solution, as our business further embraces sustainability.”

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Batteries and humidity!

The climate crisis is driving demand for the electrification of transportation and energy infrastructure, which in turn is accelerating the need for more powerful and safer rechargeable batteries, including li-ion, sodium-ion, and solid-state. However, one of the key issues affecting battery quality is accurate humidity monitoring and dry control during manufacture, and in the following article, Antti Viitanen from the measurement technology company Vaisala, explains why.

The importance of humidity.
Battery manufacture is a delicate process performed in a highly controlled, ultra-low humidity environment. Stable, accurate, fast-response dew point probes are therefore an essential component of control systems that help improve safety, yields and energy efficiency.

The midstream stage of battery manufacturing involves electrode production, cell assembly, and cell finalization. It is during these steps – in dry rooms, dry booths, and glove boxes – that humidity control is especially important to prevent unwanted reactions. These include lithium forming lithium hydroxide and hydrogen gas, lithium salt forming hydrogen fluoride (HF), and electrolyte generating corrosive byproducts. Efficient and effective drying ensures:

• protection of people and materials, because the chemicals used are sensitive to moisture and present an explosion risk if exposed to elevated moisture levels
• yield maximization whilst maintaining product quality, because excessive moisture negatively impacts the quality and therefore the lifetime of batteries
• energy optimization by maintaining dry room ambient dryness at optimal levels. This avoids over-drying and under-drying, both of which are extremely costly

Dew point measurement in solid state battery manufacturing.
The ambient dew point temperature in dry rooms is typically maintained within the range from -30°C to -40 °C, and these low humidity levels are controlled by high-end dryers. This is one of the most energy-intensive parts of the battery manufacturing process, so minimizing over-drying is key to the plant’s overall energy efficiency.

The dew point sensors in the dryer need to be highly responsive to control the dryer quickly and accurately, but it is important to note that sensor accuracy is not the only factor affecting drying efficiency. A probe with a fast response time, and without the complex internal measurement control loops of some analyzers, makes all the difference in dryer and overall dry room control. The volume of air being dried and pushed through the process is very large, so energy consumption can easily skyrocket if the drying process is not optimized.

Newer technologies such as all solid-state batteries may require drier conditions with the dew point temperature as low as -80 °C in individual processing steps. Typically, these steps are performed inside dry booths or glove boxes because it is not usually economically viable to dry the whole dry room to the same extremely low dew point level. Humidity levels in dry booths and glove boxes are therefore monitored at critical points.

Today, the most used measurement device for dryer monitoring and control is a dew point sensor based on thin-film polymer technology. Previous instrumentation suffered from drift, especially at low humidity levels, but the development of Vaisala’s DRYCAP® technology has enabled accurate, stable, and fast-response dew point measurement with minimum drift.

Maintaining accuracy in dew point sensors.
Battery manufacturers use large numbers of sensors throughout their processes to measure, monitor and control humidity levels. The cost of these sensors is negligible in comparison with the value of the assets and products that they protect. Nevertheless, it is vitally important that sensors are accurate and stable in the long-term, so it is important to select the right sensors, and to implement an effective program of calibration checks.

A key factor in choosing dew point sensors is the availability of proven reliability. This means that the providers of sensors should be able to demonstrate long-term accuracy and stability over many years, and in a wide variety of changing environments.

All sensors may deliver measurement results outside of acceptable limits for a number of reasons that may not be immediately apparent. The most important function of calibration is therefore to check results against a known standard. However, all measurement devices drift over time to a greater or lesser degree, so ensuring these sensors are properly calibrated at appropriate intervals is essential if their readings are to be reliable in the long term.

The dew point sensors used in the midstream processes of battery production are sensitive and highly accurate instruments, but calibration is necessary for more than just the avoidance of drift. For example, the accuracy of sensors can be compromised by physical damage or other environmental factors.

Calibration programs for dew point sensors.
A variety of calibration options exist for dew point sensors at battery manufacturing facilities. Handheld devices are available for quick and convenient spot-checking and on-site calibration. The advantage of this method is that probes do not need to be removed from the process and downtime can be kept to a minimum. In addition, some devices, such as Vaisala’s Indigo80, can be used as a reference probe and sent for factory calibration complete with a certificate for full calibration traceability.

Some sensor manufacturers operate accredited service centres to which swapped-out sensors can be sent for routine calibration checks. Alternatively, many battery manufacturers find it more convenient and economical to contract their sensor supplier to provide a fixed price calibration program.

Conculsion.
The purpose of this article is to highlight the potentially serious implications of failing to implement an effective humidity measurement program in battery manufacturing plants. Dew point sensors perform a critically important role, so it is vitally important to install the right sensors and to ensure that they deliver stable, long-term accuracy and reliability. To achieve this, no matter which sensor is deployed, an effective calibration routine is essential for the efficient, sustainable operation of the plant; protecting safety, energy efficiency and battery product quality.

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Impressive distribution.

GDP compliance assured at pharma distribution facility.

PostNord TPL has developed an impressive warehousing and distribution facility in Sweden, designed specifically to handle medicinal products, including both prescription and over the counter pharmaceuticals. In compliance with numerous life science industry requirements such as the Good Distribution Practice (GDP) regulations, the internal environment of this facility is carefully controlled to protect the large numbers of products that are processed every day. The warehouse is highly automated and has recently been equipped with an advanced network of humidity and temperature loggers, supplied and installed by the measurement technology company Vaisala.

The requirement to update the monitoring network was prompted by a previous supplier’s ‘end of life’ notification in early 2022. Several potential technology providers were then contacted, including Vaisala, which provided a demonstration of its wireless continuous monitoring and alarm system, viewLinc.

Background.
PostNord TPL is a part of the PostNord group and is the leading third-party logistics supplier in Sweden and the Nordic countries. The company offers the Nordic market innovative and cost-effective logistic solutions all the way from producer to consumer. PostNord TPL has of a warehouse area of roughly 700.000 square meters. It employs around 3000 people, and in 2022, had a turnover of about 3.2 billion SEK.

As key elements within pharmaceutical supply chains, PostNord TPL’s warehousing and distribution facilities operate under strict GxP requirements which include amongst other things a necessity to continuously monitor the internal environment of storage areas, and to implement appropriate alarm systems. Anyone engaged in the activity of wholesale distribution of medicinal products in the European Economic Area must hold a wholesale distribution authorisation issued by the national competent authority of the Member State where they carry out these activities. The same national authority is responsible for inspecting the wholesale distributor, which must comply with EU GDP to obtain a wholesale distribution authorisation.

System requirements.
The imminent demise of the earlier system provided PostNord TPL with an opportunity to evaluate the latest technologies and solutions on the market. PostNord TPLS’s Project Manager, Tina Fritzson says: “First and foremost, the new monitoring network needed to fulfil our GDP requirements. To achieve this, it needed to be accurate and reliable, because the previous system had regularly delivered false alarms, which wastes a lot of time. In addition, the requirement for wiring should be minimal, and ideally the system should be intuitive so that it is simple to operate.”

Vaisala Sales Manager Janne Halonen has been involved with the PostNord TPL project from the beginning. He says: “It was clear from our first meeting that we would be able to offer PostNord TPL a significantly superior system. viewLinc is more than capable of meeting their key requirements, and our validation service provides all of the necessary information to demonstrate GDP compliance,” Janne explains.

“In early 2022 PostNord TPL provided us with floorplans so that we were able to build a detailed proposal to meet their precise requirements,” he adds. “Later that year, we were delighted to be awarded the contract, which included the installation and commissioning of 102 sensors monitoring a 30 000 m2 warehouse. Most of the sensors are monitoring temperature and humidity in this very large facility, but some are also deployed in refrigerated areas that have to maintain certain pharmaceutical products between 2 to 8 °C.”

Reflecting on the system’s performance to-date, Janne says: “Since installation, the viewLinc system has worked very well, and I am confident that we have exceeded PostNord TPL’s expectations. In addition to reliable GDP compliance with a full audit trail, one of the main benefits of the system has been problem-free operation – the old system used to deliver false alarms on a daily basis, but of course that no longer happens.

“Ease of use is also a major advantage; we typically find that new operators require less than an hour’s training. A further feature, that I know PostNord TPL has found useful, is viewLinc’s facility to define the path for alarm messages, so that only those that need to be alerted are notified.” 

Data management.
The Vaisala data loggers gather readings every minute, 24/7, and data are transferred to a central server by Vaisala’s proprietary VaiNet wireless technology. VaiNet access points create links between Ethernet and Vaisala devices, and whenever a new data logger is added to the system, it is automatically identified by an access point, which forwards the data logger’s information to the server. Once accepted by the system, data loggers remain synchronised, and redundancy is achieved by allowing load distribution between VaiNet access points which share multiple in-range data loggers. The Vaisala loggers also store data for 30 days to protect data integrity in case there is a network outage. The whole system is managed by Vaisala’s viewLinc enterprise server software which assimilates the data, providing alarms, real-time data trends and GDP compliance reports. Users are able to access the viewLinc system with any web-enabled device, and a high level of security is maintained with encrypted communications and automatic data origin checks.

Vaisala RFL100 in situ

Measurement technology.
Vaisala’s RFL100 data loggers at PostNord TPL are equipped with probes containing either temperature sensors, or sensors for both temperature and humidity. The probes are detachable and simple to switch out for calibration. The viewLinc software detects probe changes and automatically updates the probe information to maintain accurate and complete historical records.

The temperature sensors are platinum Pt100 and Pt1000, and the RH probes employ Vaisala’s HUMICAP® technology. Temperature measurements do not generally suffer from drift, but traditional humidity sensors do, so Vaisala’s HUMICAP sensors are preferable because of their long-term stability and insensitivity to interferences such as dust and condensation. These thin-film capacitive humidity sensors have become the industry standard in a wide variety of applications where long-term accurate, reliable, maintenance-free humidity measurements are required.

Summary.
The Vaisala viewLinc system has now been operational since the Autumn of 2022. Looking back, PostNord TPL’s Tina Fritzson says: “We have been very pleased with the Vaisala system. The support from Janne and the field engineers has been very good; we no longer suffer from false alarms; the system is easy to operate; report generation is quick and simple, and with accurate, verified monitoring data, our GDP compliance is assured.”

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@VaisalaGroup @PostNordSverige @_Enviro_News #PAuto #Environment

Accurate and reliable room sensors.

 LtoR: CDS201, HTS201,  TES201

A new generation of accurate and reliable room sensors has been launched by E+E Elektronik. Tailored to the respective facility automation application, the CDS201 3-in-1 device for CO2, humidity and temperature, the HTS201 humidity and temperature sensor and the TES201 temperature sensor are great choices. Each variant has analogue outputs or a digital interface and a large, state-of-the-art display. The functional snap-on enclosure minimises installation costs and avoids the intake of false air.

Excellent measurement performance, innovative design.
The three sensors impress with their outstanding accuracy in terms of the physical quantities. This results from E+E Elektronik's many years of experience in the production of high-quality sensing elements.

On top of this, the elegant, functional snap-on enclosure design is exciting and available in two sizes (EU and US versions) depending on regional standards. The lower part of the housing only contains the plug-in terminals and can be installed and connected without the cover, which contains the electronics. This means that the active part of the device is not exposed to any contamination and can be fitted on the lower part shortly before commissioning. The innovative enclosure also prevents the ingress of false air and significantly reduces self-heating. The sensors are optionally available with a state-of-the-art, easy-to-read graphic display.

Interfaces and configuration.
The measured values are either delivered via analogue outputs or to the digital interface using the Modbus RTU or BACnet MS/TP protocol. The digital version with its RS845 interface can be set up and configured on a PC using the free PCS10 product configuration software and an optional configuration adapter.

Areas of application.
The new room sensors are highly suited for use in demand-driven ventilation, heating and air conditioning technology, and facility automation.

• CDS201 – The Versatile Choice - The CDS201 combines CO2, temperature (T) and relative humidity (RH) measurement in a single device and is particularly well suited for demand-driven ventilation and facility automation in residential and commercial applications. The CDS201's CO2 measurement relies on the contamination-resistant NDIR dual wavelength principle. This technology automatically compensates for aging effects, while at the same time guaranteeing excellent long-term stability. Factory multi-point CO2 and temperature adjustment ensures high measurement accuracy over the entire temperature operating range. E+E sensor coating protects the active RH/T sensing element against contamination and corrosive deposits. This results in improved measurement performance and longer sensing element life in environments with high levels of dust or soiling exposure. In addition, it improves long-term stability by preventing stray impedances caused by deposits on the active sensor surface.

• HTS201 – The Allrounder - The HTS201 is designed for accurate and reliable measurement of relative humidity (RH) and temperature (T) in residential and commercial facility automation applications.
The E+E RH/T sensing element with its patented sensing technology guarantees excellent performance over the entire operating range even in environments with high levels of dust or soiling exposure. Again, E+E sensor coating ensures long-term stability for the measurements.

• TES201 – The Efficient Choice - The TES201 is designed for accurate room temperature measurement (T) for indoor climate control. In addition to proven, high-quality E+E sensing technology, these room sensors impress with their great price/performance ratio.

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• E+E Elektronik products are marketed in Ireland by Instrument Technology.

#EplusE #PAuto #BAS

Powerful humidity and temperature sensor.

The new HTS801 sees E+E Elektronik launch its most powerful humidity and temperature sensor for industrial applications on the market. This versatile, high-end measuring device combines the Austrian sensor specialist's decades of experience in the field of humidity measurement with the high quality demands of industrial metrology. The sensing probes of the HTS801 incorporate a premium, heatable sensing element for accurate measurements, guaranteeing long-term stability even under the most challenging conditions. Additional options such as a large colour display or plug-and-play probe replacement using rapidX technology ensure user-friendly operation and easy maintenance.

The HTS801 is particularly well suited to use in applications with high humidity and chemical exposure. It is based on the E+E sensing element with monolithic structure. An integrated heater enables targeted heating of the sensing element to prevent condensation and its negative impacts on the measurement results. Depending on the requirements, two type-specific operating modes are available for selection:

"Condensation Guard" in case of a short-term risk of condensation.
"High Humidity Guard" for permanent exposure to high humidity and condensing conditions In addition to this, all HTS801 models have an Automatic ReCovery (ARC) function. ARC removes chemical impurities and eliminates possible drift effects through short-term intensive heating of the sensing element.

Furthermore, the tried and trusted E+E sensor coating protects the sensing element and its leads against corrosion or deposits. This special coating extends the sensor's service life, ensuring accurate measurement results and improved long-term stability in harsh or corrosive environments.

Thanks to its wide operating range from -80 °C to 180 °C (-112 °F to 356 °F) and 300 bar (4 351 psi), the HTS801 is suitable for a variety of applications; for example, for monitoring drying processes, humidity and temperature monitoring in fuel cell test benches, climate chambers or high-humidity storage rooms to demanding measurement tasks in meteorology and much more.

The rugged polycarbonate or stainless-steel enclosure, featuring IP65 / NEMA 4X protection, supports easy mounting and maintenance of the HTS801. 

Plug-and-Play Probe Exchange.
The HTS801 offers the option of smart, pluggable sensing probes. Every HTS801 rapidX smart probe can be exchanged without configuration, adjustment or calibration following the plug-and-play principle. The specific parameters are stored directly in the probe and are transmitted to the sensor when the probe is plugged in. This avoids downtime and costs if a probe needs to be replaced due to damage or for recalibration.

Display with Data Logging and Diagnostics Function. The HTS801 is optionally available with a 3.5" TFT colour display. This allows up to four physical quantities to be displayed simultaneously and monitored locally. The integrated data logging function stores up to 20 000 measured values per measurand. The values can be visualised on the display or downloaded using the USB service interface. Thanks to the on-board diagnostics function, the operating status of the HTS801 can be checked directly on the device.

Interfaces and Configuration.
The measured data is available at two freely scalable analogue outputs, RS485 (Modbus RTU) or Ethernet PoE (Modbus TCP) interface, and at two alarm (relay) outputs. This enables flexible integration of the sensor into customer's own data acquisition systems.

The HTS801 can be configured via the USB port using the free PCS10 configuration software or directly on the device using the display and push-buttons.

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• E+E Elektronik products are marketed in Ireland through Instrument Technology. 

 #EplusE #Calibration #Pauto

A tale of sausage skins.

Our correspondent recently purchased all of the sausages that he could find with artificial casings at his local supermarket. He then cooked them, and "yes they were as delicious as they look!"

"... as delicious as they look!

He submitted a case study which contains a useful comparison of artificial casings and ‘natural’ casings, whilst also explaining how a team of British food processing engineers developed a technique for manufacturing synthetic casings that trebled productivity. However, as he said, "every silver lining has a cloud, and much as I would like to tell you who the engineers were, they requested anonymity… sorry!"

They have developed a technique for manufacturing collagen sausage casings which protects product quality and trebles output. The process relies on precise monitoring of temperature and humidity with Vaisala sensors, combined with multi-stage feedback control.

Advantages of collagen skins.
The manufacture of collagen sausage skins from animal hide is a good example of sustainable production because it effectively recycles a potential waste product into a valuable commodity that helps to improve the quality and consistency of sausages. However, all sausage casings are delicate and require precise conditions and careful handling during manufacture, storage and distribution, and throughout the subsequent sausage manufacturing process.

Natural casings from the small intestine of meat animals tend to be variable in length, diameter and thickness, so they are not ideal for high-speed sausage manufacturing processes. In contrast, collagen casings offer reliable, consistent features, and are therefore ideal for fast, efficient processes. Also, collagen casings do not need to be stored in chilled conditions and have a longer shelf-life than traditional casings.

Collagen casings are ready to use straight out of the package, horn loading is quick and easy, and there is no requirement for soaking and untangling of bundles. There are no seasonal variations, and sausages manufactured in collagen casings offer improved cooking coverage which delivers a superior cooked appearance in comparison with sausages in natural casings.

Developing a new collagen manufacturing process.
Initially, the sausage skin manufacturer utilised a conveyorised flat sheet collagen dryer, but this incurred a level of friction that could lead to ripping and product wastage. The process was slow and wasteful, so the engineers were challenged to develop a new, less damaging technique for drying and processing the extruded cylindrical collagen cases that are used in sausage manufacture.

Sausage casings have very specific physical characteristics and need to be extremely consistent in their properties, so it was vital that the new process minimises friction whilst providing optimal levels of temperature and humidity. If humidity is too high or too low, it can negatively impact the quality of the finished product, so it was important for the equipment to be able to respond to ambient conditions, irrespective of their geographical location.

HMT120

The new processing solution allows the casings to be inflated with hot, dehumidified process air provided by a silica-based desiccant rotor. New equipment was also developed for transporting the inflated gel using an innovative handling system.

The new system employs three precision sensors. A Vaisala HMT120 humidity transmitter monitors environmental humidity, so that dry air can be recirculated when outside conditions are too humid. In addition, two Vaisala DMT345 dewpoint transmitters monitor process air to ensure that the collagen products are maintained in ideal conditions by a multi-stage feedback control system.

DMT 345

The HMT120 transmitter contains Vaisala’s HUMICAP® technology; a thin-film polymer-based capacitive humidity sensor, which delivers accuracy, reliability, long-term stability and insensitivity to condensation or contamination. The DMT 345 dewpoint transmitters incorporate the Vaisala DRYCAP® sensor, which is also designed for accuracy, reliability and stability. The sensor is condensation-resistant and is immune to contamination, however, DRYCAP’s unrivalled performance is based on its capacitive thin-film polymer sensor and an autocalibration function. The sensor also has a rapid response time and quick recovery after getting wet.

Vaisala’s Juhani Lehto says: “This engineering team routinely utilises Vaisala sensors because their food processing equipment is supplied to customers all over the world, operating in a wide variety of environmental conditions. They therefore need sensors that are more than just accurate and reliable in the long-term; they also need to have a low maintenance requirement.”

Summary.
In addition to the manufacture of collagen sausage casings, the precise measurement and control of process temperature and humidity is fundamentally important in a wide range of food and beverage processes. By minimising friction between the equipment and the casings, the new processing system resulted in less wastage, time-savings and a three-fold increase in productivity.

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@VaisalaGroup @_Enviro_News #PAuto #Food

Handheld indicator & smart probes.

A new portable Vaisala Indigo80 Handheld Indicator designed for industrial spot checking, short-term data logging, field sampling, data analysis and diagnostics has just been launched.*

In conjunction with the Indigo80, the company announced the launch of the Vaisala HUMICAP Handheld Humidity and Temperature Probe Series HMP80 and the Vaisala DRYCAP Handheld Dew Point and Temperature Probe Series DMP80; both designed for portable use, operating seamlessly with the Indigo80 handheld indicator.

Indigo80 with probe HMP80

The Indigo80 handheld combines leading-edge technology and ultramodern industrial design. Special attention has been paid to its look and feel, customer experience, and usability. It must be easy to take along and operate reliably in varying measurement environments, while being as durable as fixed installed devices. The design features of the Vaisala Indigo80 received an honorary award last year in one of the most prominent design competitions in Finland, the Fennia Prize.

“We are very proud of the product design, as Indigo80 has much more than meets the eye: it is a perfect combination of simplicity, ease of use and the highest standards of technology, accuracy, and reliability. It has an impressive list of features, including support for up to two Indigo-compatible probes or transmitters simultaneously. Its rechargeable lithium-ion battery ensures typically 10h operation time without charging, and its intuitive user interface support customers in 10 languages,” comments Product Manager Vuokko Lantz from Vaisala.

In addition to the two newly launched probes, Indigo80 operates together with Vaisala’s other Indigo compatible measurement probes and other selected Vaisala measurement instruments. Together with the selected probes, Indigo80 creates value by adding a portable measurement option in the Indigo product family for multiple parameters, including humidity, temperature, dew point, carbon dioxide, hydrogen peroxide vapor and moisture in oil, bringing ease of use and increased process efficiencies to the industrial customers.

The Indigo80 indicator’s datalogging capabilities enable the enhancement of industrial process efficiency by monitoring process conditions during the needed time period. Spot-checking helps to ensure that process conditions are within the required range to produce consistent and high-quality products.

Indigo80 can also be used for reference checking of the stationary installations of Vaisala measurement instruments, and for on-site calibration of the existing Vaisala fixed-mounted instruments to optimize process conditions.

“Industrial process optimization based on accurate data can lead to increased production efficiency, reduced waste and emissions, and improved resource utilization, which delivers a smaller environmental footprint,” Lantz concludes.

Deliveries of the Vaisala Indigo80 Handheld Indicator and the launched probes start gradually in Q2 2023 in selected countries.

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* To coincide with the launch, Vaisala has also published a Blog: Spot-checking measurements of environmental conditions!

@VaisalaGroup @_Enviro_News #PAuto  #Environment

Air quality indoors.

Extech’s new 42280A series temperature and humidity data logger features a number of notable enhancements over the company’s highly successful legacy model to ensure even higher performance and capability levels in indoor environmental monitoring applications. This latest-generation highly accurate and reliable meter will serve as an invaluable asset at any company looking to monitor the air quality of their production area, for example.

A direct replacement for the popular 42280 series, the new 42280A features the same large, triple LCD display showing temperature, humidity and date/time clock simultaneously. However, continuous improvement is embedded within Extech’s DNA, so the company’s newly developed model introduces a number of added-value functions, including the capability to generate PDF reports or Excel spreadsheets when plugging the device (via integral USB interface) into a Windows-based PC after data logging.

A further important enhancement is an increase in internal memory to 48,000 points/readings, three times more than the previous model, to suit demands for extended monitoring or monitoring at high frequency rates. The Extech 42280A also sees the introduction of a Max/Min mode and the presence of Hi/Lo indication on-screen. Here, the programmable/selectable data sampling rate ensures visual and audible alarm indication in association with Hi/Lo limits.

Adaptable to almost any situation, further features of the new Extech 42280A include a ‘mark’ function that enables users to read out the memory contents starting from a defined time without reprogramming the log. As a point of note, data remains secure within the logger at all times and can be password-protected if required.

They are also releasing their new 42280A-NIST version. This model features calibration traceable to NIST standards for indoor environments where it is necessary to demonstrate accurate and reliable measurements, supported by calibration reports that users can download to a PC.

Critical components of any indoor environmental monitoring system, both the 42280A and 42280A-NIST meters offer a temperature range from -20 to +70°C and a humidity range from 0 to 100%. The devices measure just 120.7 x 88.9 x 38.1mm and weigh only 163g. Users can choose from wall, desktop or tripod mounts in line with individual requirements. Salt bottles for relative humidity calibration are available in kit form (33% and 75%) as optional accessories.

Extech supplies the 42280A and 42280A-NIST complete with Windows compatible software, USB cable, universal AC adaptor, four AA batteries, user guide and two-year warranty for complete peace-of-mind. The meters are shipped fully tested and calibrated and, with proper use, will provide years of reliable service.

@flir @planetextech @mepaxIntPR #Environment #BAS

Keeping data centres cool.

Around 60% of a data centre’s energy requirements are driven by its IT infrastructure, so there are energy reduction opportunities in (usually new) equipment that is more energy efficient. However, there are good opportunities for energy efficiency in the other 40% of energy demand; the majority of which comes from a data centre’s cooling and air-conditioning systems. In many data centres 99.999% uptime is expected; representing annual downtime of just a few minutes, so accurate, reliable, continuous monitoring and control is essential. Here Anu Kätkä from Vaisala^* explains what must be measured, and where.

Anu Kätkä

Data centre owners and managers are acutely aware of the need for better energy efficiency. With responsibility for around 1% of global electricity consumption, the sector is heavily affected by turbulence in energy costs, so there is a very strong demand for energy efficiency. At the same time, governments around the world are looking to energy hungry industries for opportunities to reduce the use of fossil fuels and lower greenhouse gas emissions.

Around 60% of a data centre’s energy requirements are driven by its IT infrastructure, so there are energy reduction opportunities in (usually new) equipment that is more energy efficient. However, there are good opportunities for energy efficiency in the other 40% of energy demand; the majority of which comes from a data centre’s cooling and air-conditioning systems.

Efficient temperature and humidity control is important for the optimal functioning of IT infrastructure. In many modern facilities 99.999% uptime is expected; representing annual downtime of just a few minutes. These extremely high levels of performance are necessary because of the importance and value of the data and processes being handled by the IT infrastructure.

In common with all good process efficiency measures, effective energy management relies on the availability of accurate, reliable, continuous monitoring data. 

So, for data centres, what must be measured? and where?

Temperature.
Cooling and air conditioning is necessary to remove the heat generated by IT equipment; to avoid over-heating and prevent failures. It is therefore necessary to monitor temperature in the aisles and racks, as well as in all spaces, ducts in the ventilation system, cooling system pipes, and outdoors. Naturally, it is vital that the measurement locations are truly representative and that the network of sensors is able to detect any potential cold- or hot-spots.

Using HMT120

Larger data halls can be more challenging to monitor because they have a greater potential for spatial temperature variability, so it is important that there are sufficient numbers of temperature sensors to ensure that all servers are monitored. Some servers may be close to a cooling unit and others may be further away; some may be at the bottom of a rack, and others higher up, so there is potential for three-dimensional variability. In addition to a sufficient number of sensors, it is also therefore important for air flow and cooling to be optimally distributed throughout the server room.

Most data centres will need to monitor ‘delta T’ – which is commonly defined as the temperature difference between hot and cold aisles. However, in reality, the situation is more complex because there are actually four different delta Ts ⁽¹⁾ that need to be monitored if cooling operations are to be as efficient as possible.

The most obvious delta T is the temperature difference in air before and after it passes through the IT equipment. The second frequently measured delta T is the temperature difference across the cooling equipment. However, in reality, the temperature of the air leaving the coolers is rarely the same as the air arriving at the IT equipment. This is usually because of issues such as obstructions, vortices, pressure differentials, air pockets etc. that cause cold air and warm air to mix. Similarly, the temperature of the air leaving the IT equipment is frequently cooler by the time it enters the coolers. This is usually because cooled air mixes with the warmed air for a variety of reasons; all of which indicate inefficiency in air flow management.

So, the four delta Ts are the temperature differences:

1. Before and after the IT equipment
2. Before and after the coolers
3. Between air leaving the coolers and air entering the IT equipment
4. Between air leaving the IT equipment and air entering the coolers

By accurately monitoring these four delta Ts, data centre managers can gain a better understanding of the factors affecting cooling inefficiency, which can then inform mitigation and improvement measures to fine tune data centre performance.

HMD Series

In dry climates evaporative cooling is effective at dissipating heat. In cold climates direct cooling with dry, cold air can be used. In recent years, liquid cooling solutions have become popular because they are more effective at removing heat. To support this trend, Vaisala has developed a new high-quality sensor for measuring cooling / heating liquid temperatures. The Vaisala TMI110 is an immersion temperature transmitter offering a fast response with high levels of accuracy. TMI110 is an addition to the extensive HVAC product offering, including e.g. the ever-popular HMD60 for air ducts, HMT120 for indoor air measurements, and state of the art Indigo platform for most precise measurements in data centres.

Humidity.
IT equipment can also be adversely affected by humidity; low levels increase the risk of static electricity, so spray or evaporative humidifiers may be necessary. However, high levels of humidity are also to be avoided because they can result in condensation, and the corrosion of metallic equipment.

In cooler climates it may be possible to utilize colder outside air to cool data centre equipment in a process known as economization. The absolute water content of this outside air may be low, and since the relative humidity of air decreases when it is heated, the humidity level may fall below acceptable levels unless appropriate controls are in place.

Different types of humidity measurement are required, depending on the location and application. For example, relative humidity and dew point can be measured in rooms, spaces, ducts and outdoors, whereas wet bulb temperatures would be necessary in cooling towers and evaporative humidifiers, and enthalpy sensors may be required for airside economizers. Enthalpy expresses the total heat energy (sensible heat and latent heat) involved with thermodynamic changes. These calculated humidity parameters are typically available directly from advanced humidity sensors, such as Vaisala’s.

The three most common sensor configurations for airside economizer control are dry bulb, single enthalpy, and dual enthalpy. While dry bulb control is the simplest method, it may miss potential energy savings by not opening the economizer when the ambient temperature is slightly warmer but relatively dry.

Dual enthalpy works in a similar way, except that two enthalpy sensors are employed; one monitoring outdoor air, and the other return air. The economizer will run if the outdoor air enthalpy is less than the return enthalpy.

Vaisala’s transmitters are designed specifically for applications such as air conditioning and economization; measuring humidity and temperature, with derived outputs for dew point, wet bulb temperature and enthalpy. Temperature measurements do not generally suffer from drift, but traditional humidity sensors do, so Vaisala’s humidity sensors employ HUMICAP® technology which delivers long-term stability and insensitivity to interferences such as dust and condensation. These thin-film capacitive humidity sensors have become the industry standard in a wide variety of applications where long-term accurate, reliable, maintenance-free humidity measurements are required.

Air flow in ducts allow sensors to respond quickly to changing conditions, whereas air movement in rooms and other spaces can be slow, so some data centres prefer to use dew point temperature as a humidity control parameter because it does not depend on the temperature of the sensor.

WXT530

Other sensors that may be deployed at data centres measure differential pressure in ducts and between hot and cold aisles, as well as additional outdoor meteorological parameters such as air pressure, rainfall, wind speed and direction. These measurements can be undertaken by an automatic weather station, by individual sensors, or by one of Vaisala’s WXT530 instruments, which utilize solid state technologies to minimize operating and maintenance costs. Outdoor sensors should be placed in a location with free airflow, away from any surfaces that might radiate heat and disturb measurements. Naturally, outdoor measurements must be as accurate and reliable as indoor measurements, so Vaisala’s world-leading meteorological instruments provide the long-term reliability that is required in even the harshest environments.

Summary.
Investments in accurate, stable measurement systems are negligible in comparison with the value of the systems and information held by data centres. Add the financial and environmental costs of energy inefficiency to the equation, and you have a hugely compelling case for a comprehensive monitoring and control system utilising the most accurate and reliable sensors.

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^*Anu Kätkä is responsible for Global Product Management in Vaisala’s Industrial Measurements. With her background in the management of growth companies in the field of intelligent buildings, she has extensive experience in building automation and building management systems, as well as metering and monitoring solutions. She is passionate about businesses dealing with advanced technologies that create true value on a global scale while also contributing positively to the environment. 

¹ The 4 Delta T’s of Data Center Cooling: What You’re Missing. (Upsite)

@VaisalaGroup @UpsiteTech @_Enviro_News #Environment #Datacentres