GE Humitrac 4-20mA Output NI 9203

[MeCoOp]

I have a GE Humitrac 4-20mA output relative humidity, temperature sensor that I am using with the the NI 9203 board and the cDAQ 9174.  Currently I have the (+) from the power supply going to the V in (I1RH/P+) terminal of the sensor.  The RH RTN (I2RH/P-) terminal connected to AI0 of the 9203, the Temp RTN (I2-TMP) terminal is connected to the AI1 of the 9203, and the com (-) from the power supply connected to the com of the 9203.  Both channels are set up in MAX for 4-20mA.  I get zeroes on both channels when measuring ambient.  The manual for the sensor can be found here Humitrac Manual.

Any suggestions?  Thanks in advance.

[Efrain_G]

Hi there,

Just to make sure that you can read values other than zero, I would try to connect a known voltage value (like a battery) between your differential terminals. Also make sure that your differential terminals are not touching. You can use a Test Panel in the Measurement and Automation Explorer for simplicity.

[MeCoOp]

Thanks for the reply.  I'm not sure I understand your suggestion, the NI 9203 is a +-20 mA board.  Could you please elaborate?

Thanks.

[bon2b]

Hi Clad,

Your connection looks OK to me. Have you selected the dip switch SW1 and SW3 on your sensor to current position? I would create a 4-20 current signal using a process meter and see if NI 9234 could see this signal if I were you.

[MeCoOp]

It was my scaling factors!  I created my curves using 4-20 instead of .004-.020, lesson learned

[bon2b]

That happened to me as well!

It's nice to hear you got your problem solved!