K type thermocouple circuit

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mikeu
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K type thermocouple circuit

Post by mikeu » Wed Dec 03, 2008 10:47 am

Hi,

Does anyone have a circuit or a link to a circuit that raises a K type thermocouple to a voltage suitable for a data acquisition card?
The input ADC has a range of +/- 10 Volts.
Thanks,

Mike

Bigglez
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Re: K type thermocouple circuit

Post by Bigglez » Wed Dec 03, 2008 2:00 pm

mikeu wrote:Does anyone have a circuit or a link to a circuit that raises a K type thermocouple to a voltage suitable for a data acquisition card? The input ADC has a range of +/- 10 Volts.
Sure, both ADI and Maxim have K-type ICs.

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reloadron
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Post by reloadron » Wed Dec 03, 2008 3:20 pm

Any particular range of temperatrures you wanted to measure with a Type K TC?

The ICs Bigglez mentions are a good starting point but would need some added amplification to get a higher voltage output. Also, you need to look at the temperature range.

Would this be a home or work project and how many channels of temperature did you want to monitor?

I recently did a small home project using four channels of Type J (I used Type J simply because I had a mile of J wire). I used several small TTs (Temperature Transmitters) I had. The object was to monitor several temperatures in a computer case.

Parts of the project (what's left of it) :smile: can be found here:

http://www.bearblain.com/case_temps_.htm

I wrote the software to read my little A/D which was scaled for 0 to 400 Deg. F. The object was to look at various temperatures with the CPUs at idle and 100% load and make comparrisons. The software form is named Hardware Logic as I did it for a computer forum.

If something like that is where you are going I may be able to help.

Ron

mikeu
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Post by mikeu » Wed Dec 03, 2008 3:37 pm

Hi,

Thanks for all the info.
I found the Analog Device chip after I posted the request.
As it turns out, the thermocouple can't respond fast enough to the event I'm trying to capture.

Mike

Bigglez
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Post by Bigglez » Wed Dec 03, 2008 4:22 pm

mikeu wrote:As it turns out, the thermocouple can't respond fast enough to the event I'm trying to capture.
I wonder if that's due to the electronics?
I was under the impression that a thermocouple
can be made very small, with minimum mass,
and respond to rapid temp changes. I worked with
someone who did an academic project to measure
the temp rises on rocket motors!

Can you share with us what project you're trying
to measure?

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