Fluke TIR32 calibration

Hi Everyone,

I just got a Fluke TIR32 and I am learning how to run it. It was purchased second hand with unknown history.
It seems to work very well and has excellent sensitivity to small temperature differences.
It has one issue. It over reads temperature by quite a bit ie 20c. (35f)
When it is first turned on, the error is less, maybe 8-10c but it gets worse as it warms up.
Any Ideas? Am I doing something wrong or does it need a calibration?

Sounds like it needs to be sent in to Fluke…

How have you determined that the temperature is off?

I have emissivity set to .95, T set to 100, BG set to ambient.

I did a bit more experimenting with it and the temps are obviously way out.
Boiled a kettle of water> it reads 46c instead of 100c. sometimes the walls read 46c and the room is 25c. (40f difference)

As the kettle heated you could clearly see the heat spread and the background wall getting cooler relatively as the colors scaled. The temperature just read WAY too low.
Opened the freezer at -18c…it reads 38c (thats about 100f!) Fridge was about the same.

I have tried auto and manual scaling with no improvement.

It is depicting very small variations in temperature beautifully. Plug in your phone to charge and the gun shows the charging cord is warmer than ambient. The temperature readings are just way out of wack.

I have searched for a firmware update with no success. Does anyone know of any firmware updates or factory reset procedures?

Also, when I first turn on the gun, and pick a fixed target, as the gun warms up and continues to calibrate (NUC) the Temp indicated slowly climbs. In between calibrations, the color temp slowly climbs as well…

You want to check your calibration against known temperatures and emissivities (e.g., 100°C boiling water and 0°C icewater), with a fully warmed imager, immediately after a Non-Uniformity Correction, under proper focus. https://www.infraspection.com/product/successiries-108/

From what you have done already, it sounds as though your imager may well be out of calibration, in which case it would need to go back to the factory or a 3rd party calibration facility.

The next question to ask is what are you using your imager for? A lot of applications do not require actual temperature determination but are focused specifically on observed thermal patterns. Unless your application requires actual temperature determination, you may be fine with an uncalibrated imager, provided the sensor is still delivering adequate sensitivity, NUC, span and focus function still work properly.

Hi Chuck

Very valid point. I am primarily interested in Qualitative analysis. Even running at 100% perfect calibration, this isnt the instrument for accurate Quantitaive measurement of temperature. I would prefer it be more accurate as there are times when the numbers do matter.

I am pretty sure it need to go in to fluke or a calibrator to have it serviced. I have noticed an anomoly ( I think) which may be related to the measurement accuracy.

I don’t think I can post a picture so I will describe the issue.
Lets say I am focused on a wall with a uniform temperature, using picture in picture. The center of the IR overlay will have a circle that is uniform and the outer corners of the PIP show colder. As I sweep along the wall, the corners of the PIP move as I move the gun.

I think there may be an optical issue with lens or sensor alignment.
It is lens vignetting with the outer portion being seen as colder.

I guess you now know why it was for sale…


I would expect consistent behavior in that regard whether PIP is turned on or off. As an FYI, few experienced thermographers that I know use PIP as it significantly reduces the screen real estate available for you to assess what the infrared component of the image is displaying.

I used to see what you are describing (without PIP) in an older FLIR EX320 that I used. I could usually attribute it to the imager not being normalized with the ambient temperature where I was shooting. For instance bringing the imager in out of a hot vehicle, turning it on and trying to use it right away.

Try making sure that the imager is acclimated at the temperature of the area that you are using it. That it has had adequate time after startup to warm fully and has completed several NUC cycles. If you start to see vignetting in the image try forcing a manual NUC if your imager accommodates it. The NUC should clear any vignetting.

Still cant manage to upload an image on here looks like i would need to host it somewhere else…

I have a few image captures that don’t show vignetting, but most do. I think you are right about complete warm up time on that front. Maybe the compressed temp range is exaggerating that.

I seems to be seeing a very narrow temp range. In either AUTO or Manual. I took a shot with a boiling kettle 100c, a hand 38c and a wall with a temp of about 26c. the entire temp span it sees and sets is 51.5-58c

I tried manually setting a wider span but it isn’t seeing it.

I’m going to get ahold of some repair/calibration guys Monday and see what they figure.
I got a good price on the imager knowing it would likely need a bit of work.

I’ll report back when I know more.
Thanks for all the help so far!