Optical absorption sensor

Sensor employs optical absorption for interface detection, measuring suspended solids and turbidity, and detecting phase separations and product loss.

The OUSAF11 sensor for measuring optical absorbance by a process fluid has been introduced by Endress+Hauser. Using visible and near-infrared wavelengths of light, the OUSAF11 is ideal for product loss detection, interface detection, and suspended solids and turbidity measurements.

The sensor emits light in both the visible and near-infrared regions, and absorption by the process fluid is determined using an optical sensor mounted in the sensor head. The sensor is available in an immersion model for use in open tanks and basins, or in an insertion model with Tri-Clamp or Varivent connections that meet 3A Sanitary Standards.

The body of the rugged OUSAF11 is constructed of 316L stainless steel. The measuring head contains the light source and optical sensor, and it’s constructed of FEP fluorocarbon film. The fouling-resistant sensor head contains no glass. The FEP fluorocarbon film is non-reactive, highly transparent, resistant to sunlight, and has a high temperature rating. Additionally, FEP is accepted by 3A for sanitary applications.

The sensor can be operated continuously up to 194 ºF (90 ºC), and up to 266 ºF for up to two hours, allowing it to be used in hot CIP processes.

It is easy to install and commission. The sensor can be installed in a pipe, with the appropriate fitting, or suspended in an open channel or basin. The integrated cable is easily wired to the transmitter. The menu-guided interface on the CVM40 allows the sensor to be set up quickly. Interface to the transmitter can also be accomplished using a keyboard and the USB port on the transmitter.

The OUSAF11 sensor operates with the Endress+Hauser Memograph CVM40 graphic transmitter and recorder to form a complete measurement system.

The CVM40 has a full-color graphic display, built-in web server, and Profibus, Modbus, Ethernet TCP/IP and RS232C/RS485 communications. It has four optical channels for input from sensors, and two universal analog inputs that accept voltage, current, RTDs, thermocouples and other standard inputs. Outputs include up to six relays, a 4-20 mA output and digital pulse outputs. The instrument can support a range of sensors in addition to the OUSAF11 with its six digital input channels.

The CVM40 can be field or panel mounted. The CVM40 can also be programmed with math functions and linearization capability to output in a preferred unit of measure.

Applications for the OUSAF11/CVM40 measurement system include food & beverage, mining, and similar processes. For example:

• Dairies can closely monitor process and effluent streams for product loss.
• CIP systems can be monitored to ensure milk/water interfaces are detected more precisely, resulting in water usage and treatment cost savings.
• Breweries can monitor interfaces, such as beer and yeast solids.
• Mining operations can perform suspended solids measurement in liquid streams using the visible wavelength capability.

When ordered, the sensor and transmitter are tested and calibrated together as a system, ensuring optimum performance.