D/P transmitters accept either gage or differential pressure pneumatic inputs that are converted to a proportional 4-20 mA output signal. This two wire signal loop is compatible with typical process components that accept analog input including PLCs. KING-GAGE® D/P Transmitters are also offered in hybrid versions combined with an air flow control for pneumatic sensors or downpipe (bubbler) systems. These units allow for direct 4-20 mA output from the tank with power provided by the receiver. LiquiSeal D/P purge control is a fully integrated air purge regulator and level transmitter. Operation is based on the control regulating a continuous 1 cfh (cubic foot per hour) flow of compressed air into the tank downpipe. An internal differential pressure sensor element converts resulting pressure into a 4-20 mAdc two wire signal.