Hi, im looking at Pressure sensors, to measure the pressure experienced at the end of a line in water.

 

However, they are all rated in PSIA or PSIG

 

And im confused I just need PSI

 

Any help clearing this up would be greatly appreciated

Atmospheric pressure will decrease by about .036 PSI for each 1000 feet of elevation. In some process systems, it may be necessary to know if an indicated pressure includes or excludes atmospheric pressure. To distinguish this, two specific pressure units are used - pounds per square inch gage, or PSIG, and pounds per square inch absolute, or PSIA.

 

PSIG is reference to atmospheric pressure and the measurement instrument will indicate zero when not connected to the process pressure, with the sensing element exposed to atmospheric pressure.

 

PSIA is referenced to absolute zero. Absolute zero is the pressure measurement when all the pressure exerted by the atmosphere has been removed. A pressure measuring instrument designed to indicate PSIA will read 14.696 pounds per square inch at sea level, when it is not connected to process pressure, and the sensing element is exposed to atmospheric pressure.

thanx that was exactally the info i needed