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 from several down-hole sensors, automatically applying barometric compensation.

Our PSIG (gauge) sensors utilize a vent tube in the cable to allow the device to reference atmospheric pressure. The resulting gauge pressure measurement reflects only the depth of submergence.

We also offers a PSIS (sealed gauge) pressure sensor. This is an absolute sensor to which 14.7 PSI offset has been included to account for air pressure. Thus the measurements reflect only the pressure due to depth, when assuming a standard barometric pressure of 14.7 PSI. Measurements with this sensor will vary slightly due to barometric and weather changes.