Testing low frequency sensors.

Accelerometers and velocity meters are used to measure a wide range of frequencies, including low frequency vibrations found in building maintenance. They occur at less than 2Hz, and can also be useful in monitoring bearing wear in cooling tower fans and gearboxes for example.

To characterise the performance of its low frequency sensors in that range, which is too low for most test shakers, Monitran has developed a new high displacement test rig that can generate oscillations accurately at frequencies as low as 0.2 Hz. The system allows real-time back to back testing between different devices and its own inbuilt, calibrated MEMS sensors.

“The new oscillating beam rig gives us accurate extreme low frequency data and is a highly useful addition to our accelerometer test and calibration capabilities,” said Andy Anthony, Monitran’s managing director.

The horizontal linear beam oscillator has a powerful motion control system that incorporates a precision AC servo with 17 bit encoder feedback. Running on two precision rails, it uses magnetic springs and magnetic damping to ensure smooth operation.

Its software produces fast code, at 1.7 milliradians per step, which generates fine sinusoidal motion for the linear track driven by a rotary motor.

The intelligent shuttle, which can carry a sensor payload of up to 0.5 kg, incorporates seven MEMS accelerometers, signal processing and a microcontroller to monitor its motion. It also includes a mechanical low pass filter and has an operating distance of up to 1000mm, exerting up to 8g acceleration to the devices under test. That amounts over 35 kilometres per hour peak velocity, down to nearly 1/20th of walking speed.

 @MonitranLtd #Pauto

Condition monitoring made easy!

Versatile and user-friendly MTN/5000 condition monitoring system

The MTN/5000, a cost-effective and versatile microcontroller-based condition monitoring system has been launched by Monitran.

The MTN/5000 can have up to 12 channels (to be specified when ordering) and features a 3.5 inch TFT touchscreen and an easy-to-navigate menu. The user is able to set data sampling rates (up to 1million/second), input ranges and resolution and alarm levels, on a channel-by-channel basis or across all channels.

The system is designed to work with Monitran’s accelerometers and velocity sensors but it can also accommodate most other sensor types including those for measuring temperature, pressure, displacement and proximity. It can also accept a voltage or current as input, and raw signals are made available at BNCs on the front panel.

As standard the MTN/5000 has 12 digital I/O channels which can be used for multiple alarms or as a communication channel for integration with other systems. Also, as an optional extra, the system can be fitted with Modbus TCP/IP, for networking purposes or to enable multiple MTN/5000s to operate together within a larger monitoring or control system.

Andy Anthony, Managing Director of Monitran, comments: “With the MTN/5000 we’re providing engineers with a versatile tool that can provide a picture of the health of plant and equipment, raise alarms and indicate when further investigation may be warranted.”

The MTN/5000 system is made to order and, in addition to specifying how many input channels the MTN/5000 should have, the user can request front panel customisation, such as asset numbering. The system requires an input voltage of 24V DC and the enclosure dimensions, including glands, are 372 x 250 x 200mm.

Anthony concludes: “The MTN/5000’s ease-of-use is remarkable. It is a turnkey solution and you don’t need to be a condition monitoring expert to get the system up and running and protecting plant and process assets.”

Investigating aero-engine technologies!

Monitran supports the Oxford Turbine Research Facility in its investigations into future aero-engine technologies

Monitran is providing specialist engineering services to the Oxford Turbine Research Facility (OTRF), part of the Department of Engineering Science, University of Oxford (GB).

Monitran has designed and is supplying high-accuracy signal conditioning units for interfacing with hundreds of thin film heat transfer gauges; which the OTRF has fitted to a full working section of a turbine in order to investigate a variety of turbine blade cooling techniques.

Kam Chana, Commercial & Technical Director of the OTRF, comments: “While we could have outsourced to a traditional CEM we selected Monitran because of their engineering professionalism when it comes to taking on specialist projects and their considerable experience in conditioning small signals.”

Working from schematics provided by the OTRF, and using appropriate CAD software, Monitran designed a double-sided, eight channel analogue circuit board. Each channel is isolated and particular attention was paid to the use of ground planes to screen signal paths into high gain amplifiers. The boards, which are housed in a 19-inch rack system, have been tested at sample rates of 1MHz, as the rationale behind the OTRF’s use of thin film heat transfer gauge sensors is that they have response times in the order of 1μs.

Andy Anthony, Managing Director of Monitran, comments: “This was and continues to be a very interesting project for us and we’re pleased to be supporting the Oxford Turbine Research Facility and the University of Oxford in their investigations into future aero-engine technologies. Also, the service we’re providing gives further testimony of our ability to undertake bespoke projects and deliver professionally engineered ‘turnkey’ solutions.”

To date, Monitran has manufactured 20 signal conditioning units for the OTRF and is on hand to produce more if required; and another reason for the company’s selection by the OTRF was its ability to deliver consistent quality.

Radiation-resistant accelerometers

Accelerometers are ideal for long-term vibration monitoring in harsh radiation environments.

The MTN/1100-R series of radiation-resistant constant current accelerometers has been launched by Monitran.

Developed for use in nuclear power stations, the sensors, which are top-entry and sealed to IP67, have a radiation resistance of 10Mrads and are well-suited for long-term vibration monitoring in a variety of harsh radiation environments.

Andy Anthony, Managing Director of Monitran, comments: “As a manufacturer of sensors, and with our talented engineering department, we pride ourselves on being able to develop and make fit-for-purpose sensors, whatever the requirements.”

Monitran’s MTN/1100-R series accelerometers have a frequency response of 2Hz to 10kHz ±5%, a dynamic range of ±80g and a standard sensitivity of 100mV/g; with other sensitivities available upon request.

Mounting options include ¼”-28UNF, for the MTN/1100-R, and Monitran’s own Quick Fit mount, for the MTN/1100Q-R.

Vibration meter for maintenance engineers

The MTN/VM220; a compact, handheld meter for measuring vibration and temperature levels has been launched by Monitran.

The MTN/VM220 conforms to ISO10816-3 and is ideal for detecting the early signs of component wear or failure in machinery, motors, gearboxes, pumps and other mechanical assemblies. The meter includes a crisp, colour LCD display and has the ability to store up to 100 readings (temperature and acceleration, velocity or displacement) against a real-time clock.

Measuring just 122 x 78 x 28mm, the MTN/VM220 has an easy-to-grip, tough rubberised case and a long-life rechargeable battery. It is supplied with a probe into which is integrated a dual-output, general purpose sensor, the MTN/2200T, which has default sensitivities of 100mV/g and 10mV/oC. Also included are a magnetic base and spike (for use with the probe), a coiled cable (0.5m nominal to 2m extended) with a 4-pin Lumberg connector at each end, and a universal (battery) charger; all in a foam-lined and durable carry case.

Andy Anthony, Monitran’s Managing Director, comments: “We’re extremely pleased with the look, feel and performance of our new vibration meter. Also, having hinted late last year that the meter was to be launched at Southern Manufacturing & Electronics, we’ve already received enquiries and advance orders from customers.”

Virtual revamp!

Monitran’s new website gives engineers easy access to product information and support services

Designed with ease-of-navigation for sensor identification and selection in mind, the new site details Monitran’s extensive range of products and the company’s value-added services. The site includes; product selection guidelines, installation and maintenance tips, frequently asked questions (FAQs) and pages devoted to specific industries, including wind energy, mining and paper.

Andy Anthony, Monitran’s Managing Director, comments: “We’ve structured the new website as an engineering resource, respecting that engineers will mostly benefit from easy and multiple ways of finding the most suitable sensors for their applications.”

Even from the Home page visitors to the site can fast-track to vibration sensors with AC outputs (for analysis), vibration sensors with DC outputs (for monitoring), eddy current probes (for proximity measurement) or LVDTs (for displacement measurement). Alternatively, the Products page lists all sensors and accessories which can then be filtered by one of 42 attributes, for example ‘High Temperature Industrial’, plus the entire site can be searched for key words.

Anthony concludes. “When designing a website it’s very easy to concentrate on the aesthetics and gimmicks, at the expense of giving the content and the site’s functionality sufficient attention. With the new Monitran website our starting point was to ask ourselves how, as an OEM, can we help our valued customers make informed decisions on which sensors to use for any given application? We also wanted to draw attention to the fact that, unlike most other OEMs, we have an experienced engineering team able to undertake complete turnkey projects.”

Guarding the Hovercrafts' drivetrains!

Monitran is supplying Southampton-based Griffon Hoverwork with condition monitoring systems for 12 of its Griffon 8000TD hovercrafts, ordered by the Indian Coast Guard.

The system, designed and developed by Monitran as a turnkey solution, employs 14 MTN/1100W general purpose constant-current analysis sensors with AC outputs, sealed to IP68 (submersible) and supplied with marine-approved cables. These feed into a bulkhead-mounted waterproof cabinet that contains 14 MTN/8066 g-mac signal conditioning units.

Each g-mac unit provides analogue (AC) outputs proportional to velocity and peak g, which feed into a PCB-mounted microcontroller programmed by Monitran to drive a touch-screen display on the front of the cabinet. Several screen views are available but the most useful show:
The current numeric mm/s values of all sensors;
The mm/s values of all sensors shown as a bar chart, with each bar showing current value, threshold and maximum value recorded; and
The mm/s values of all sensors as lines on a 360o dial.

All of the above also include a colour-coded status indicator; green to denote below-threshold and red to denote above-threshold.

The cabinet also feeds a status indicator in the hovercraft’s cockpit to give the pilot an indication of vibration levels.

Tony Roxburgh, Project Manager of Griffon Hoverwork comments: “A hovercraft’s drivetrain experiences a wide range of loads, in terms of torque and RPM, during operation as it tends to be worked hard when a crew is responding to an emergency. The Indian Coast Guard requested that their 8000TDs be fitted with an integrated engine and gearbox vibration monitoring system to warn the pilot if the drivetrain experiences any abnormal vibrations.”

Other requirements included that the system be lightweight, compact, compliant with marine regulations and itself tolerant to high levels of vibration. In addition, provision had to be made for maintenance engineers to view the vibration levels on any given sensor in order to identify which component(s) might be wearing or developing faults; a requirement that was easily met thanks to each g-mac having a buffered native accelerometer output presented on a BNC connector.

Andy Anthony, Monitran’s Managing Director, comments: “Monitran is increasingly undertaking turnkey projects, and developing engineered solutions from the sensor up. The project with Griffon Hoverwork also exemplifies what can be achieved with a relatively humble, general purpose accelerometer like the MTN/1100W.”