We are trying to measure level on an reflux accumulator with a Honeywell DP. The accumulator is under vacuum -26 inHg, a temp of 343.05 degC, and the liquid has a S.G. of .8360. Our sight glass is showing 75% and the dp is reading 35%

 

1) what range is 100%? 1", 10" 100"? 10mm? 100mm? 1m? 10m?

2) Are you using remote seals? Or impulse tubing ?

3) Has it ever read properly, or is this a new installation issue?

 

> 1) what range is 100%? 1", 10" 100"? 10mm? 100mm? 1m? 10m?

> 2) Are you using remote seals? Or impulse tubing ?

> 3) Has it ever read properly, or is this a new installation issue?

Further to david's comments, it seems that your reading is inverted. It seems that your LP leg of te transmitter is equipped with a reference pot (vessel which fills itself up with condensed fluid from the vessel). If this is the case then your reading becomes inverted, as at minimum level in the main vessel there is maximum differential pressure difference on the transmitter, and vice-versa at high main vessel level. You need to reprogram your transmitter such that 100% output occurs at minimum differential pressure, and 0% output at maximum differential pressure