So I think I am having some issues with my mavic 2 enterprise when using the thermal imaging modes. A few things here. So I was flying yesterday and getting some temperatures of turf athletic fields for my job. The Thermal imging mode seemed to be working decently well but my colleagues and I thought that the temperature gauge may be not working quite right because we have tested these field before and know one to be much hotter than the other since they were built with different materials. However, today the drone showed the hotter field to be cooler which was very strange. Then after that I was flying over some nearby tennis courts and when I switched from 'visible' mode to 'ir' mode the screen was just grey, no image or outline whatsoever and said everywhere was 32 degrees farenhieght which is just false as it was a 90 degree day. Later I turned my drone back on the grey screen was gone when I switched to IR mode and was in color as it should be. When my screen went all grayed out I kep tweaking settings to try and get color but nothing. It seemed like a drone restart did the trick (even though I shouldnt have to do that in the first place).

My main concern here is that the temperature gauge/sensor is wrong. So has anyone had a similar experiecne to this and have advice? Is it possible my temp gauge is slightly broken?

Thank you!

Hello,

I've had the same kind pf problem. I tested my M2E Dual last week, it was about -1°C outside and sometimes the blue spot of the thermal camera showed temperatures on my roof at -8.5°C, there were even spots where it was down to -11°C... Can it be real ?

If someone else has that problem,please let me know !

Thanks.

The thermal camera is automatically auto-calibrated and can give + - 2 degrees from the real temperature. it must at least work at outdoor temperatures for about 20 minutes to have any stabilization. Another serious influence is the distance every 10 meters the camera realizes a difference of -1 degree down. If you read 10 m 5 degrees at a distance of 30 m it will take you 2-3 degrees and depending on the size of the object. The only option is to examine the camera and make your own adjustment table.

Hola, comparé con flir one pro y flir XTR 640 mi M2EA Y SOBRE 40° marcaba 10° mas, bajo 40° todo normal, equipo nuevo, nunca volado

I've just noticed something similar with mine.
The temp readout is showing approx 10c lower than the actual temperature.
Is there a way to calibrate?

I'm wondering the same.
Taking temperature readings indoors at room temperature with my M2EA seems to yield correct-ish results but flying outdoors with an ambient temperature between -20C - +5 degrees C, results become totally off. Measurements from my metal garage roof in +5C ambient temperature gives a reading of -20C. Measurements of the ground (a dirt field) in -10C ambient gives a reading of -21.1C
What am I doing wrong?
I've tried both manual and automatic FFC but it doesn't seem to do anything.
The 'user guide' isn't very helpful either. It doesn't even explain what the FFC is supposed to accomplish, nor does it provide any guidance in its use.

Hello,
With thermal imaging cameras, the material of the surface to be measured plays a major role. The so-called emission factor depends on the material. There is a big difference whether you have metallic surfaces or e.g. want to measure plastic surfaces. This can be easily proven with an adhesive tape. If you apply adhesive tape to a metal surface, the measured temperature will be higher, or rather, more accurate.

Extract from the user manual:

The accuracy of temperature measurements is influenced by various factors
a) Remission of objects - shiny metals with high remission reflect more background radiation and result in lower accuracy, while objects with matt surfaces achieve higher accuracy.
e) Emissivity of objects - the emissivity of an object affects the accuracy of temperature measurement. In general, the accuracy increases in proportion to the emissivity. The emissivity is influenced by factors such as the material, the roughness and the degree of oxidation of the object surface.
This applies to all infrared cameras! With some infrared cameras you can adjust the emission factor, this is particularly the case with industrial cameras. The smaller the emission factor of a surface, the less precise the measurement. Metallic surfaces are very difficult to measure and also act like mirrors and therefore show incorrect temperatures.

Examples:
                                                         Emissivity ε (-)
Absolutely Black Body                            1
base metals                                    0.016 - 0.050
painted surface                                0.92 - 0.95
human skin                                            0.98

In general, the higher the emissivity, the more accurate the measurement.

Hi and thanks for chiming in on this subject!

I'm aware of the emissivity factor but my problem with MUCH too low readings is 'constant' over a plethora of measured objects and materials. I've measured concrete, bricks, soil, trees, glass, metal (roof) and various plastic composites. They all reads more than 10 degrees C off (downward) from the expected values. I've let the M2EA sit for a while on the ground to acclimatize and I've been flying for around 25 minutes without any sign of improvement in the readings. To me it seems like the sensor is calibrated for ~room temperatures and values close to or below zero confuse the microbolometer. Also , I can't find ANYTHING about correct usage of the FFC function in the manual. How am I supposed to use this and when should I toggle 'AUTOMATIC FFC CALIBRATION' on or off? I would guess that some sort of reference surface must be used - but what and how?

If I'm not mistaken, the M2EA is specified to be operable down to -10 degrees C...

Hello, is the gain mode set low or high? With high gain (range -20°C to 150°C), the accuracy should be +-2°C or +-2% for a black surface. At low gain, the camera can deviate significantly more.
The FFC calibration does not change the displayed temperatures. The FFC calibration ensures that the image is scaled with the smallest and highest temperature value. This is just for the better representation of the image.
However an infrared camera is not a precise temperature measuring instrument, but it is very good at showing temperature differences.
I hope I was able to help. If you still think the camera is faulty, then I would contact DJI.

In the case I described I had the gain set to HIGH. This problem is especially bad in cold weather. All readings become skewed linearly it seems. With a factory of -20 deg Celsius.  Like if I'm measuring temperature acclimatized soil or whatever, at 0 degrees Celsius ambient, I will get readings in the -20 region.


/M