LVIT sensor drift

Anyone have any idea what would cause an LVIT to drift? I have an omega LDI-119-050-A020A, 4-20mv, sensor that is hard mounted on a fixture that clamps something with a little hydraulic hand pump. The LVIT sensor is hooked up to an omega panel meter.

I've calibrated the sensor but it drifts over the course of just a day by several thousands of an inch. We have been using a dial indicator that is accurate so I can tell that the LVIT is drifting.

Any ideas? This is the second sensor i have put in there so i don't thin the sensor is bad.

Does the temperature change over the course of the day?

The temperature coefficient for that transducer is 0.015% Full Scale / Deg C

0.002" would relate to a change of about 7 Deg C [12.6 DegF].

ndzied1 said:

Does the temperature change over the course of the day?

The temperature coefficient for that transducer is 0.015% Full Scale / Deg C

0.002" would relate to a change of about 7 Deg C [12.6 DegF].

Click to expand...

No the room is temperature controlled and it doesn't change more than 10 Deg. F. The changes i am seing are up to 0.015" if not more.

Is it possible that it is being over extended or under extended? If I read the specs right it is only 50 mm range that is not a lot of movement.

doctord said:

Is it possible that it is being over extended or under extended? If I read the specs right it is only 50 mm range that is not a lot of movement.

Click to expand...

No, I am only using about a 1/4 of the travel. Right in the middle.