Sanitary Point-Level Sensor

ifm efector inc. introduces the LMT Series Sanitary Point-Level Sensor that is designed to monitor the level of liquids, viscous media and powders in food and beverage processing tanks and pipes. The sensor can provide reliable level indication in storage tanks and protects pumps from run-dry conditions.

Viscous media, such as ketchup and mayonnaise, tend to stick to a sensing face and cause unreliable level indication. ifm's LMT sensor uses high frequency (MHz) capacitive spectrum profiling technology that enables the sensor to ignore foam and deposit build-up and differentiate between actual product in a tank or only residue.

The LMT's capacitive technology allows the sensor to detect measuring points at multiple frequencies which enables deeper penetration into the media. The LMT "sweeps" the frequency band of 50...200 MHz taking three measuring points: electromagnetic field damping, permittivity phase shift of the molecule polarization in the magnetic field, and the media conductivity in the electric field.

An internal sensing algorithm processes these measurements to calculate the signal amplitude. Only when actual media is present does the signal amplitude value occur at the correct frequency and switches the sensor. The combination of field damping, conductivity, and permittivity results in an efficient residue suppression.

The LMT sensor meets food and beverage sanitary requirements and features a PEEK sensing face with a food-grade surface finish. A 316 stainless steel body ensures chemical compatibility even with the harshest cleaning agents. A high protection rating of IP68/IP69K prevents liquid ingress. Laser-etched part numbers won’t deteriorate in high pressure cleanings.

The factory settings on the LMT sensors is established for different types of media which eliminates sensitivity adjustments. The LMT 100 is set for water-based medium and the LMT 110 is set for oils and greass. Typical applications include level monitoring in storage and mixing tanks, pump monitoring to prevent run-dry conditions, and reliable media level in pipes.  The Micro DC sensor provides a PNP, normally open / normally closed output.