Non-contacting transmitters for level control
Published: 13 January 2012 - Heather Ramsden
Emerson Process Management has extended its range ultrasonic non-contacting level transmitters. The Rosemount 3107 and 3108 transmitters work with the 3490 controllers to provide combined measurement and control of level, volume (tank contents) or open channel flow using flumes or weirs, in industrial and water utilities applications.
Both transmitters have a 12-metre measurement range and are 24V loop-powered devices with 4-20mA and HART communications. They are supplied factory-sealed in an IP68-rated UPVC housing complete with integral cable and stainless steel mounting bracket. They can be used as standalone devices or as part of a site-wide measurement, control and data acquisition system.
Differential measurements can be made using two Rosemount ultrasonic transmitters and a single control unit. The system is easily programmed to display the difference or sum of the two levels or flows. The Rosemount 3108 features a remote temperature probe, making it suitable for open channel flow measurement when greater accuracy and precision are required. Designed to overcome inaccuracies due to ‘solar gain’ when the sun shines directly on transmitters installed in the open air, the compact unit has a remote temperature sensor with a two-metre cable making it easy to mount the temperature sensor in a shady spot.