FP-PT100 FieldPoint Dual Channel Temperature Module doesn't work as expected.

[Puho]

Aaron, are you there?...We are having important diferences between several environment temperature mesures, all done with FP-PT100 modules and OMEGA RT series 3-wire sensors. It looks like having a permanent offset of 6 or 7 celsius degrees at FP-PT100 modules. Example: Environment temperature mesured with conventional termometer is 25 degrees, and the value read with FP-PT100 through FP-1600 and FieldPoint Explorer is 32 degrees. Could you help us?
Best Regards,
Eduardo

[steven@ni]

Eduardo,

Try changing slots. More than likely, however, the module is miscalibrated and will probably have to be sent in or replaced.

Can you check the measurement with another fp-pt100 module or another rtd? Let's make sure that it isn't a faulty terminal base or rtd.

Also, how are you wiring the 3-wire rtd?

[Puho]

Dear Steven,
We have confirmed than almost all those modules are miscalibrated. We have measured -4,xx and -2,xx Celsius degrees like offsetts in two modules. By the same way, it is very important to know the exact length of cabling from PT100 sensor to FP-PT100 module, in order of adjust the final measured values. Question: Is it possible to calibrate the FP-PT100 2 wires modules in our laboratory?
Best Regards,
Eduardo

[steven@ni]

I doubt if both the modules are miscalibrated.

How are you wiring the modules - are they correctly wired.

It almost sounds as if there is a common mode voltage or some offset due to wiring. Check the wiring again.

Also, as you said, wire length will increase common mode voltage and thus offset your readings.

Try a short rtd and recheck the wiring and let me know the results.