How to measure heat from electronics
How to measure heat from electronics
(OP)
Hi All,
I'm trying to find (and purchase) some type of apparatus that will allow me to measure how much heat is being put out by various electronics at different ambient temperatures. Does anyone know of something that will allow me to do this and where I would find it?
Thanks for your help.
I'm trying to find (and purchase) some type of apparatus that will allow me to measure how much heat is being put out by various electronics at different ambient temperatures. Does anyone know of something that will allow me to do this and where I would find it?
Thanks for your help.





RE: How to measure heat from electronics
Here are a few:
www.GoInfrared.com
www.telogyllc.com
www.x20.org/thermal/
Expensive. .
RE: How to measure heat from electronics
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RE: How to measure heat from electronics
Thermal imaging cameras or IR thermometers measure temperature, not heat.
RE: How to measure heat from electronics
I've been looking for a calorimeter, but haven't been successful finding one that would work. Basically I'm looking for a controlled environment box, maybe 5 ft by 5 ft, that I can set to various temperatures. Then I'd place the components inside and it would be able to measure how much heat (in watts) the device was putting out.
I would even be willing to have one custom made if anyone knows of a company that would do something like that.
I appreciate the replies thus far.
RE: How to measure heat from electronics
RE: How to measure heat from electronics
heat generated =(power in) less ( power output }
or neglecting signal input power
for efficiency is defined as
power out = eff x (power in), then
heat generated = (power in) x ( 1-eff)
so the thermal wattage is equal to power in only for 0% efficiency.
Most heat test are done in a flow tunnel with controlled air flow unless nat. convection is sought and monitored temperatures.
RE: How to measure heat from electronics
An exception would be if it's a fairly efficient radiator of power in another form (radar maybe? or light?) -- in which case you might need to subtract the amount of power that is known to leave in the form of electromagnetics instead of heat.
Good on y'all,
Goober Dave
RE: How to measure heat from electronics
RE: How to measure heat from electronics
For example: I am driving four CREE MC-E multichip LEDS at 12W each for a total of 48W. All four of them are driven via a single device, but it only dissipates 150 mW of power. The remainder goes to the LEDS and line losses in the traces on the board. This illustrates that power in is only equal power out when the entire control volume is considered. Each component has it's own contribution to power dissipation and efficiency.
RE: How to measure heat from electronics
If not you could just turn it off when it is at the temp you want.
RE: How to measure heat from electronics
The reason that you can't just turn it off when you get to where you want to be is because unless you have reached steady state then you would be shutting off in the middle of your transient. Unless that's how you intend your devices to perform, it's not going to give you the real set point but only a data set of one, and you can't get any meaningful data from a single point.
RE: How to measure heat from electronics
> Insualted vat of Fluorinert, or similar
> Measure starting temp
> Dunk board in and power
> Measure ending temp
> Multiply specific heat by deltaT and divide by test duration
TTFN
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