TC CJC Accuracy

[ASTDan]

Hello,

I noticed that the USB Thermocouple module has 1 degree F of accuracy for the CJC.  Is there a way to improve this i.e. external CJC Thermocouple using an ice bath?

http://www.ni.com/pdf/manuals/371566e.pdf

What products/techniques can be used to improve this accuracy.

Thanks

Dan

[hrh1818]

On May 7, 9:10 am, ASTDan <x...@no.email> wrote:
> Hello,
> &nbsp;
> I noticed that the USB Thermocouple module has 1 degree F of accuracy for the CJC.&nbsp; Is there a way to improve this i.e. external CJC Thermocouple using an ice bath?
> &nbsp;
> <a href="http://www.ni.com/pdf/manuals/371566e.pdf" target="_blank">http://www.ni.com/pdf/manuals/371566e.pdf</a>
> &nbsp;
> What products/techniques can be used to improve this accuracy.
> &nbsp;
> Thanks
> &nbsp;
> Dan

The document you provided a link to shows that the 9211/9211A has a
raw analog input mode. Hence you could use a combination of an ice
bath for your cold junction reference and the raw analog input mode to
measure the output of your thermocouple.

Howard

[Joseph_Loo]

I do not see how you got the 1 deg F accuracy. I looked at the curve andsee a 1 deg C minimum at certain locations. You did not state what tempeature range you are looking, In addition, you did not specified what type of thermocouple you have, if it is a special calibrated thermocouple. In general, thermocouples are +/- 5 deg F depending on your thermocouple. If you need that kind of accuracy, I suggest looking at thermistors or rtd.