The immersion probe comprises oa measuring cell, two-wire transmitter and a special cable with capillary tube. The housing comprises stainless steel with a pressure-sensitive diaphragm that is protected with a stainless steel cap. The level signal is determined by the pressure difference between the water column over the probe and atmospheric pressure which is transferred to the probe through the capillary tube. This differential pressure is converted to a 4...0 mA analogue signal by the piezo-resisive cell and the fitted electronics.