Good day,

As per the above mentioned subject and photo attached, would you be able to advise on how to perform calibration of this instrument?
Pressure was applied on the positive side of the gauge with the low side being vented. However, the readings observed at 25% increments are approximately 10-15 Bars off. Can a T-150 DWT be used as the master for calibration and verification of this instrument?
Thank you in advance for your kind cooperation and attention to this request. Look forward to hearing from you at your earliest convenience.

Regards,
Naresh

 

It's a differential pressure gauge, subtracting the applied pressure on the presumed (-) low side from the pressure on the high (+) side and indicating the difference.

Assuming that the low side port is marked with the (-), it looks like the (-) side is open to atmosphere so the DP gauge, as installed, is acting as a gauge-pressure gauge, referenced to atmosphere.

To check its calibration, you do what you did: apply a known pressure to the port with the (assumed High side) marking (+), leaving the low side (-) port open to atmosphere; essentially the same as one would do when calibrating a standard gauge-pressure gauge, the typical gauge with a single port. This would be the same calibration technique even if the installation used applied pressures on the low (-) side.

The Vactra web site has minimal info, nothing on the accuracy range of the gauge.

I have no idea what a T-150 DWT is, other than assuming DWT is a dead weight tester. Any dead weight tester that can supply sufficient pressure to accomplish the calibration/verification and has certification required by the customer will be suitable.

 

Hello David,

Thanks for your reply!
My apologies for the T-150 DWT abbreviation. You're correct; it's an Ametek T-150 model dead weight tester.

Thanks
Naresh