What are PSIA (absolute), PSIG (gauge), and PSIS (sealed gauge) pressure sensors and how do they differ?

PSIA (absolute) sensors measure the depth plus the atmospheric pressure. This atmospheric pressure must be subtracted from the absolute pressure to give the actual pressure due to depth. For information on using the Barometric Compensation utility to perform these calculations, refer to the Barometric Compensation Utility application note. In addition, the AquiStar Compensator obtains readings …

My pressure readings are zero.

Continuous zero readings are usually caused by an open circuit, which may indicate a broken cable, a bad connection, or possibly a damaged sensor. Check the connector to see if a wire has become loose or if the cable has been cut. If damage is not readily apparent, contact INW/Seametrics support for evaluation and repair.