Determining component temperature

Thread Starter

Robin66

Joined Jan 5, 2016
275
Does anyone have a recommendation for a digital thermometer or the like to determine a component's temperature within a reasonable tolerance? So far I've been working on the basis:
  • 40c+ if it feels warm
  • 60c+ if it's too hot to keep my finger on it
  • 100c+ if a licked finger sizzles on it
I'm stress testing a DC-DC converter and motor-drive and I want to know how I can expect the behavioiur the components to vary with temp. according to the datasheet.

I have one of these but it's not at all suitable. It can't make good contact with the component and it has a poor response time.
http://www.ebay.co.uk/itm/Digital-F...epid=0&hash=item41a412df26:g:9zcAAOSwL7VWiXFL
 

Thread Starter

Robin66

Joined Jan 5, 2016
275

ian field

Joined Oct 27, 2012
6,536
Does anyone have a recommendation for a digital thermometer or the like to determine a component's temperature within a reasonable tolerance? So far I've been working on the basis:
  • 40c+ if it feels warm
  • 60c+ if it's too hot to keep my finger on it
  • 100c+ if a licked finger sizzles on it
I'm stress testing a DC-DC converter and motor-drive and I want to know how I can expect the behavioiur the components to vary with temp. according to the datasheet.

I have one of these but it's not at all suitable. It can't make good contact with the component and it has a poor response time.
http://www.ebay.co.uk/itm/Digital-F...epid=0&hash=item41a412df26:g:9zcAAOSwL7VWiXFL
The pistol grip pyrometer thermometers can be pretty cheap these days - but read reviews before parting with money.

Apparently there's IR cameras - not cheap, and I doubt the calibration is all that good.
 

Thread Starter

Robin66

Joined Jan 5, 2016
275
Ok thanks for this. I've bought a pistol grip pyrometer for £10. The reviews are overwhelming positive. One of the main critical points was that the error can be ~2c which is a small error for most (non-medical) purposes.
 

mcgyvr

Joined Oct 15, 2009
5,394
Be aware that with a "pyrometer" like that you need to be VERY accurate with the "emissivity" setting or the results will be pretty inaccurate..
And that setting will change from component to component/spot to spot based on its surface color/roughness,etc... Also the spot size you choose makes a big difference too..
Most if not all safety agencies will NOT allow those types of devices to be used for any meaningful measurements..

Thermocouples are a better choice for thermal profiling of electronic components and are accepted by the safety agencies...

I have the first gen Flir One for Android phones.. Its a great little device to use to know where your warmest components are so that you can attach thermocouples more accurately for final measurements..
http://www.flir.com/flirone/
At $199 its hard to beat that compared to most thermal cameras in the thousands of dollar range..
Looks like they are releasing a new generation though as its preorder for anything on those pages..
 

Thread Starter

Robin66

Joined Jan 5, 2016
275
Ok well I'd be happy with accuracy within 5c, so I can take black plastic components as being high emissivity and tinned tracks as being low emissivity, and play with the dial a bit to get a feel for the error margin. I can already tell which bits of my board are the hottest without using an imaging camera.
 
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