Technique for Board Temperature Readings with IR Gun?

[XtraGood]

OK so this is a pretty simple one I'd think but I'm still learning the basics and didn't find it with search. How does everyone take temperature reading of their LED boards when tuning in drivers? I have a QB96 and an A type driver. After leaving the light on to stabilize its temp, do you turn the light off and quickly hit it with the gun or do you stick the gun under there while its on and just click around at the emitter surface without looking until you get the highest reading?

 

[JavaCo]

Throw the Ir away and get a thermocouple . The IR won't be very accurate on a lot of surfaces. https://www.amazon.com/Proster-Thermocouple-Thermometer-Dual-Channel-Thermocouples/dp/B071V7T6TZ/ref=pd_sbs_328_27?_encoding=UTF8&pd_rd_i=B071V7T6TZ&pd_rd_r=f289e16e-4d47-4fa4-bfab-ad79c82ab0f5&pd_rd_w=PYPlX&pd_rd_wg=68xxX&pf_rd_p=bdd201df-734f-454e-883c-73b0d8ccd4c3&pf_rd_r=6PFDVHXE3G1E0556YW81&psc=1&refRID=6PFDVHXE3G1E0556YW81

 

[Rocket Soul]

For accurate IR measurements (or at least as good as they get) use the ir meter with a black surface: some black tape if its raw aluminium

 

[Airwalker16]

If you MUST use an IR, some black paint on The back of it is your best bet. Tape will be pretty close but might be a few degrees cooler than what it really is.

 

[XtraGood]

Throw the Ir away and get a thermocouple . The IR won't be very accurate on a lot of surfaces. https://www.amazon.com/Proster-Thermocouple-Thermometer-Dual-Channel-Thermocouples/dp/B071V7T6TZ/ref=pd_sbs_328_27?_encoding=UTF8&pd_rd_i=B071V7T6TZ&pd_rd_r=f289e16e-4d47-4fa4-bfab-ad79c82ab0f5&pd_rd_w=PYPlX&pd_rd_wg=68xxX&pf_rd_p=bdd201df-734f-454e-883c-73b0d8ccd4c3&pf_rd_r=6PFDVHXE3G1E0556YW81&psc=1&refRID=6PFDVHXE3G1E0556YW81

I'll get one of those. There's not a ton of space for tape but if I can't take the wait for delivery I will try tape too. Thanks for the help.

 

[XtraGood]

I got one of those duel probe k-couple thermometers. Whats the best place to take the readings? I jammed one probe into an empty screw hole right next to the edge of the board on the front of the light and have the second resting on the heat-sink (71C and 67C at 185 wall watts). The IR gun reads 67C on the back of the heat sink and 100C when aimed at the front of the board.

Any tips for getting the best readings and keeping boards at the right temps?

 

[XtraGood]

(Excuse the poor man's testing rig.)

I wired two in parallel, the probes on the back of each are stable at about 48C (w/in 1/2 degree of each other) with the driver maxing out at exactly 250watts on the kill-a-watt. I'll be using this as my setup for all of them. Will suck when one board dies/disconnects and the other fries, I should probably get some fuses?

 

[JavaCo]

I got one of those duel probe k-couple thermometers. Whats the best place to take the readings? I jammed one probe into an empty screw hole right next to the edge of the board on the front of the light and have the second resting on the heat-sink (71C and 67C at 185 wall watts). The IR gun reads 67C on the back of the heat sink and 100C when aimed at the front of the board.

Any tips for getting the best readings and keeping boards at the right temps?

Most chips have a TJ point for thermal measurements, not sure if QB96's have them or not. I would check with the manufacturer and see if they have a data sheet with the info in it. Most recommend a thermal adhesive for mounting the thermocouple to a chips TJ point but you can use a really sticky high quality tape for heat sinks so you can reuse the probe.

 

[Airwalker16]

Most chips have a TJ point for thermal measurements, not sure if QB96's have them or not. I would check with the manufacturer and see if they have a data sheet with the info in it. Most recommend a thermal adhesive for mounting the thermocouple to a chips TJ point but you can use a really sticky high quality tape for heat sinks so you can reuse the probe.

Soldering a wire to the tj is easiest. You just heat it back up to release it

 

[XtraGood]

Instead of doing 2 boards to 1 driver like I said (because I was concerned about shortening the lives of the drivers), I started putting some together that are one driver to one board run at under 185 watts at the wall each. Leading back at my original temp concerns. With the probe just setting on the back of the heat sink it reads 58C to 62ish depending on the board. I've got a bit before they'll get run long term except for testing, hoping to figure out where to solder to before then. I sent off an email to HLG service dept about finding the Tj point a day or two ago.