Water pressure on a differential transducer

[gls]

I've been trying to find why a differential pressure transducer with two silicone filled sensors connected to the transducer does not read a pressure underwater.
I'm told the unit is completly liquid filled but should read
a difference in water depth depending on the distance of the two sensors (max of 20'). I belive its because there is no air gap in the unit to cause any deflection of the transducer. I don't think the water pressure reacting on the sensors would be enough to cause enough deflection for it to give a reading since it's scaled for 0 to 300" H2O. Any comments or ideas where I could find a reference to this would be appreciated. Thanks

 

[Ron]

It is more likely that you HAVE an air bubble in the sensor line. Water should act directly on a liquid filled sensor.

Make sure your line has no bubbles at the sensor location.