Thermocouple configured in NI-9221 module

[tajim]

Dear all!

Good day!

I am trying to configure 6 K-type thermocouples via NI-9221 Analogue input module and cDAQ-9174 chassis. Shall I be able to get the direct temperature readings out of this module since it is not a thermocouple module??? If not?? Kindly suggest me how to do get direct temperature readings from this NI-9221 module!! A prompt help will be highly appreciated!

Best regards!

Tajim

[Broken_Arrow]

---

tajim wrote:

[...]

NI-9221 Analogue input module and cDAQ-9174 chassis. Shall I be able to get the direct temperature readings out of this module since it is not a thermocouple module??? I

[...]

---

Not easily, or accurately. Thermocouples need precise, very low voltage amplification. What you really need is a 9211, but you probably know that. Try Omega Engineering for a Thermocouple to Analog converter. This will get expensive for multiple wires, and you will be so much better off the the 9211.

[Seth_B. · Accepted solution]

To build on what Broken Arrow said, the 9221 is really not at all optimal for thermocouple measurements.  Most thermocouple measurements take place between 0 and 80 mV.  The NI 9221 is a 12-bit module with a ±60V range.  Your code width for this module is about 15 mV and your accuracy is 156 mV.  All of your thermocouple readings will be lost in the noise for this module.  I would recommend either the 9211 or the 9213 for thermocouple measurements, as each has CJC and is specifically designed for thermocouples.  If you want to try an external amplifier, that may work, but you'll likely need something that can amplify from 0 to 80 mV up to 0 - 60V.

Regards,

[tajim]

Dear fellows!

Thank you very much BrokenArrow and Seth B. for your quick reply!! I just wanted to have an expert advise and a technical reason which Seth has provided. Thank you very much for saving my time since I just wanted to try this module NI-9221 for thermocouple measurement. Have fun!

Regards!

Tajim