temperature data with NI USB 6218

[aero_b]

Hi friends,

I have a question. I need a card to acquire and generate different types of data. NI 6218 card seems suitable but there is no information about temperature data on its spesifications. Does anyone have an idea if 6218 is suitable for temperature data? 

[nyc_(is_out_of_here)]

http://sine.ni.com/nips/cds/view/p/lang/en/nid/201881

[aero_b]

But i do not prefer two different hardware. it is better if it is all in one

[GerdW]

Hi aero,

maybe you should define the term "temperature data" before asking for specifications?

That 6218 card has a minimum voltage range of 200mV, so you could even attach thermoelements as analog input - with limited accuracy that should work...

[aero_b]

i have planned to use K type thermocouples

[GerdW · Accepted solution]

Hi aero,

K-type TCs have a sensitivity of ~41µV/K, while the 6218 specs give a minimum accuracy of 88µV (with a sensitivity of ~5µ).

So you will receive an accuracy of ~2K for your measurement - as a rough estimation...

If that's ok for you: just try it...

[aero_b]

Thank you GerdW.

Last question, what is the relationship between voltage and kelvin with K type thermocouple

[GerdW]

Hi aero,

so you ask here about the internal workings of a thermocouple? Did you ever tried to use Google or Wikipedia? They provide good explanations/information on that topic...

I already wrote "~41µV/K" - what else do you need to answer your last question?

[mebels_meta]

Would an RTD work with the USB-6218? At .385 ohms/C it would seem it should work. Assuming it would what would be teh best way to connect it? My thought would be a voltage divider and a differential input.

[Hooovahh]

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@mebels_cti wrote:

Would an RTD work with the USB-6218? 

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Since the 6218 doesn't measure resistence the easy answer is "no" this is not the right hardware.  But given a custom circuit which can have a known scale from resistence to voltage, and then apply that scale, then the more difficult answer is "yes".