How do you monitor the temperature of electronic components?

[MacIntoshCZ]

Hello, how is this done in practice? Do you have a thermal camera that scans a certain part of the room and beeps when a certain temperature is exceeded? - Can't there be an emissivity problem? I am currently checking everything with the unit302c infrared thermometer.
thanks

 

[Pommie]

You design the circuit so it doesn't overheat and when it starts to fail you can look for hot components and work out what went wrong.

Mike.

 

[ronsimpson]

I have a calibrated finger. At 50C it jumps off the part.

Infrared thermometer (point and shoot) thing. Wish I had a camera.

 

[KeepItSimpleStupid]

A camera is a nice tool. Stuck with a IR thermometer with laser pointer. The big problem is image size. It;s a fluke, but I don;t like the fact that there is no shutter. I had/have a DMM contact/thermometer from Fluke as well. I forgot if I replaced the sensor. The IR thermometer has a K type input. I also have a fluke thermocouple meter for nearly all thermocouples.

 

[Nigel Goodwin]

I have a calibrated finger. At 50C it jumps off the part.

You just need to make sure you lick your finger first - then it doesn't get burnt, and you hear the saliva boiling off before you feel anything.

 

[Visitor]

Keep in mind when using an IR thermometer:

The IR sensor's field of vision is cone shaped — the angle varies depending on the unit, but it's relatively wide. The temperature measured is not the temperature at the laser spot. It's the average over the field of view of the sensor. A relatively large circle around the laser dot.

 

[MacIntoshCZ]

Keep in mind when using an IR thermometer:

The IR sensor's field of vision is cone shaped — the angle varies depending on the unit, but it's relatively wide. The temperature measured is not the temperature at the laser spot. It's the average over the field of view of the sensor. A relatively large circle around the laser dot.

View attachment 130651

Yes,
when measuring mosfet do you measure on plastic body? And what emisivity should be set for plastic package? I used to measure heatsink becouse reading on mosfet package is way lower.

 

[Visitor]

The specs for the Uni-T UT-302C say the Optical Resolution (D:S – Distance:spot) is 20:1. This is quite good, meaning if you're measuring from a distance of 20cm, the spot size (measurement circle) is 1cm. If you measure from 10cm, the spot size would be 5mm.

 

[Visitor]

Yes,
when measuring mosfet do you measure on plastic body? And what emisivity should be set for plastic package? I used to measure heatsink becouse reading on mosfet package is way lower.

I would take the highest reading you can find. You can be certain the temperature of the package is greater than the temperature of the heatsink.