SparkFun Forums 

Where electronics enthusiasts find answers.

Have questions about a SparkFun product or board? This is the place to be.
By jayjay
#8041
Hello Guys

I am looking into non contact temp sensing using a thermopile, but I am a bit lost on interfacing and signal conditioning the thermopile sensor. Most standard thermopile sensors seem to haev 4 pins for example this TPS333

http://optoelectronics.perkinelmer.com/ ... 333_R3.pdf

Does anyone have any suggestions for wiring this up and possibly interfacing it to a ADC in a MCU?

TIA
Cheers
Jay
By JonChandler
#8046
Hi Jay,

Looks like you've got your work cut out for you to make one of these work. A little research found a couple good references on the web.

The first explains just what a thermopile is. Essentially a series of thermocouples, with a thermistor to measure the temperature of the sensor itself. The thermopile measures the incident radiation, from which temperature can be calculated. See the info here:

http://www.fuji-piezo.com/Thermopile.htm

This means that you have small signals to work with.

Another link on the web shows a sample circuit of how to make it all work. Amplication is required because of the small signal levels - this circuit handles the amplification and the temperature compensation. It also covers calibration and gives some info on the (non-trival) calculations needed to determine temperature. See it here:

http://www.thermometrics.com/assets/ima ... mopile.pdf


Jon
By jayjay
#8069
Jon

Thanks for the reply, I had gone thru the links before posting. the second link from GE has a schematic model, but without any part values and I have difficulty selecting the right OP-AMP :-(

Cheers
Jay