FP-TB-3 CJC calibration

[tfulop]

The FP-TB-3 has a CJ imbeded into the TB. This is not calibrated separatly but is used in conjuction with FP-120. The FP-120 is calibrated for CJC but is never linked to the TB. There should be a system calibration between the TB and FP-120 and be used togheter?

Do you know the thermistor type used in the FP-TB-3?

There is a posibility to measre the thermistor propertise from the terminals?

[DangerDave]

Hi tfulop,

Just in case, have you taken a look at the FP-TC-120 and cFP-TC-120 Operating Instructions manual?

The document itself can be found here:

https://www.ni.com/docs/en-US/bundle/373344a/resource/373344a.pdf

It seems to mention the FP-TB-3 several times.  If you search for FP-TB-3, you may find the information you're looking for!

[Stephen_Moore]

Does this help?

There are three different thermistors that are currently being used in our FieldPoint terminal bases and are recommended for CJC.

The thermistor needs to be connected between pins 36 and 37 in order to function properly.

Model     Part Number
U.S. Sensor     PT502J2
BetaTHERM     5K3A1
Sensor Scientific     WM502C


Each of these thermistors are interchangeable, negative temperature coefficient (NTC) thermistors with 5kohm @ 25 C, +/- .2 C. Specifications for the thermistors can be found at the manufacturers website.

The important characteristic of these thermistors is that the resistance vs. temperature ( R vs. T) curve is similar between them. Also, each thermistor contains a beta value for the R vs. T curve, which produces similar results across the specified temperature range. Although different thermistors may contain closely matching beta values, the R vs. T curve may be different and may not perform as expected.

Cheers

Stephen

[tfulop]

Thanks, right what I was looking for.