NI 9219 DAQ with LabVIEW - RTD measurement

[AndreaD]

Hi,

I'm not sure which category this would go with - Multifunction DAQ or LabVIEW. So right now I have two NI-9219 data acquisition set to measure 8 RTD's. The command I am using is DAQmx Create Channel (AI Temperature-RTD) I am able to capture 8 RTD's, all set to the RTD setting PT3851. The Ro value I am supposed to set to is 1000 ohms - however if I have it to this setting, the values I am obtaining are really far off. If I set the constant to 2000 ohms, it appears to give the correct temperature readings. I'm not sure if I undrstand why this is the case?? Is it because there are two devices, therefore the Ro would need to be set to 2000 ohms - just  not sure why I need to set it to 2000 ohms instead of 1000 ohms. 

Thanks,

Andrea

[Henrik_Volkers]

First you (we) need to know the type of RTDs you are using and how it is wired to the DAQ.

If you are using platin RTDs the R_0 is usually 25,100,500,1k (or 2k?) . disconnect the RTDs and measure them with a multimeter at room temperature to check it. 

(If you have calibrated sensors, the R_0 is noted in the calibration report, however check it anyway)

[doloy]

How to use ni 9219? I need install Rtd 3-wire. Please tell me the tutorial to set up rtd

[GovBob]

I'm no expert but you could start by reading this.

[doloy]

I have installed in my 9219,I was following intruction from https://knowledge.ni.com/KnowledgeArticleDetails?id=kA03q000000x1rnCAA&l=en-US , but it didn't work. if the measurement was araoun -200 C, is it normal?

[DECONN]

Hi doloy,

Here are some other useful articles worth looking into:

https://www.ni.com/en/shop/data-acquisition/sensor-fundamentals/measuring-temperature-with-thermocou...

https://www.ni.com/en/shop/data-acquisition/measurement-fundamentals/field-wiring-and-noise-consider...

I would suggest starting with a simple Test Panel in MAX to verify signal readings and reference device pinouts. These can also be found in detail in the user manual alongside other helpful wiring diagrams.

https://www.ni.com/docs/en-US/bundle/ni-9219-getting-started/page/overview.html

If you are still having difficulty, post a list of your specific hardware setup, wiring details, and channel configurations.