Has anyone done a comparison of a thermocouple to infrared. If so what are the down falls. We have attempted it but our camera is reading higher than the thermocouple. The only way we can get a matching temp with the thermocouple is set of emiss to 1.04 which is impossible. Any help with this issue would be greatly appreciated.

We have numerous questions along these lines in bearing temperature measurements. . We never have found one single answer except a number of factors to think about.

Some things to consider:
• Camera can read the hottest spot in the square. If the temperatures are not uniform, you might not be reaching this hottest spot with the thermocouple. Take a look at max/min/average in the image.
• The temperature probe mounted to a surface amounts to a heat sink and can alter the temperature of the piece that it is measuring. Take a look at probe on the surface with your cameera. If you see a cool spot there then you know the probe is influencing the measurment.
- Both the camera and the thermocouple have some small allowable inaccuracy even when operating properly. You can check your camera and your probe on other known standards if you want to make it a research project.
If you have low emissivity surface of course that raises other questions including correct value and more reflection effects. If you can see an effective cavity on the surface and if it is within your MFOV, the emissivity there should be pretty close to 1.

If your ONLY concideration is to get your IR camera to the exact temperature to your T/C readings and you cannot because your IR temps are higher at an E=1.00, then simply increase your background/Tamb/Reflected temp. setting to higher than the target temperature.

This will result in lowering temp. when your lower your camera's E value.

Now, please note that this in NO is telling you that you are "Accurate" in your temps. It is simply a means of getting corresponding temps between T/C and IR.

Now as to your T/C accuracy problem, it really depends on the T/C equipment you are usinsing. Is it the partable hand held units, is it the embeded T/C???

Whith T/C, accuracy is dependant of Time and Good Contact. Remember a T/C does NOT measure the objects temp. Rather it measures the temp of itself.

I personally will always trust my IR camera and calibration techniques over any hand held portable T/C.

Hope this info helps.

Please excuse the spelling mistakes. It was too early on a Saturday Morning!