Capacitance transmitter is compact in size and employs surface mount technology in an encapsulated module. It monitors level change by converting the movement of liquid refrigerant on the probe into a pulse wave form that is proportional to the level in the vessel. Series P fromH.A. Phillips & Co. has 4 to 20 mA isolated output signal, maximum span of 4,000 pF, I0.25% repeatability, and minimum probe temperature of -60°F (-76°C). The transmitter utilizes a 24 VDC current loop for power source for signal transmission and is available for direct immersion into a vessel.
July/August 2000, RS# 228