How can I get 0.01 "C resolution for thermocouple

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necromancer

Joined: 05 Jan 2005
Posts: 34

31 Oct 2009 20:08 How can I get 0.01 "C resolution for thermocouple

Can I just use AD595 or high resolution(24 bits) ADC to meet this requirement?

FvM

Joined: 22 Jan 2008
Posts: 5159
Helped: 767
Location: Bochum, Germany

31 Oct 2009 20:29 How can I get 0.01 "C resolution for thermocouple

You are asking for 0.01K resolution rather than accuracy, which seems appropriate. It implies about 0.5 uV voltage
resolution. It's generally feasible, but low frequency noise and offset drift can endanger it. Unfortunately, the AD595 has
no noise specification. If the input stage is similar to other ADI instrumentation amplifiers, it should work. In any case, a
suitable low-pass filtering respectively averaging should be provided.

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flatulent

Joined: 19 Jul 2002
Posts: 4875
Helped: 324
Location: Middle Earth

31 Oct 2009 21:55 Re: How can I get 0.01 "C resolution for thermocouple

Other aspects are the temperature range and repeatability. Most of these metal type temperature sensors are sensitive to shock and vibration and there is some hysteresis.