Resolving Incorrect Sign in Setra FLEX

If The FLEX is a pressure sensor: Verify the tubing. The high pressure port needs to go TO THE SPACE OF CONCERN and the low goes to the REFERENCE SPACE.

If the FLEX is reading a voltage value: Verify the inputs/outputs are configured correctly on the display and verify that the customer has wired the device properly

My suggestion to resolve the difference: The difference in the values could be the fact the customer did not zero the sensors out and they are seeing a pressure offset with an accuracy difference.

Open the doors between the space of concern and the reference and zero out the FLEX. There can be a difference in values depending on the accuracies of  all the pressure devices.