The LMT Series sanitary point-level sensor from ifm efector inc., Exton, PA, is designed to monitor the level of liquids, viscous media, and powders in food and beverage processing tanks and pipes. The device uses high-frequency (MHz) capacitive spectrum profiling to ignore foam and deposit build-up and to differentiate between product and residue. It sweeps the 50–200 MHz frequency band and measures the electromagnetic field damping, the permittivity phase shift of the molecule polarization in the magnetic field, and media conductivity in the electric field. An algorithm then calculates the signal amplitude and determines whether it occurs at the correct frequency (meaning media is present), at which point it switches the sensor.
ifm efector inc.