What the eye cannot normally see - what an IR camera tells us on a cold morning

[MrBadger]

Decided to pop out this morning with my IR camera attachment. Hard ground frost and a good heat source sometimes reveals things that the eye cannot.

I'll add to the images as I scan through to find some interesting ones. Car was on full auto condition whilst these were being taken. Unfortunately my camera was slightly out of calibration when some of these were taken.

First up, front camera heater and heater wire running along passenger (in UK) side of screen.

 

[MrBadger]

And a possible air leak around the roof glass - IR detected it before it thawed

 

[MrBadger]

A few final random images

Door mirror heaters and rear screen defrost. for info - manually selecting rear heater will turn on door mirror heaters.



Some forum comments suggest that there may be airflow around door handles to help defrost. If this does happen there no evidence that it is particularly effective. These images may simply be showing temp differences due to different materials and you will see from other images that its not that obvious from a distance.



An odd one here as I am not familiar with the rear quarterlight configuration. But evidence of drivers side warming at faster rate than other side windows - deliberate or just consequence of warm airflow?



No evidence of warming side B pillar cameras



Different heating effect in rear wing including noticeable warming below rear quarterlight on passenger side. I suspect most of the difference is material type and construction. I wonder if there may also be slight air leak on drivers side rear edge of door.

 

[Glan gluaisne]

The door handles will give a massive error on a FLIR camera, due to the very low emissivity of the chrome surface. If the FLIR is the same as my Seek Thermal camera, then it will be calibrated for an emissivity of about 0.9, as this matches most non-shiny stuff. The emissivity of a chrome finish will be around 0.058, so way below the calibration figure for the sensor.

The way around this is to stick a bit of thin masking tape to the chrome. After enough time for the temperature to stabilise the bit of masking tape should give a true temperature reading, as the surface of masking tape has an emissivity of ~0.93, pretty close to the sensor calibration emissivity.

 

[Avendit]

Awesome! Have to say I was up with my Flir this morning too, but taking pics of the house to ID additional insulation work.

Would these pics of the roof be enough to get it re-seated at a service center? Given both the IR and melting patterns there is obviously a problem there!

 

[vitesse]

I noticed when my MS windscreen was being replaced that there are heating elements under the area where the wiper blades park. I was just wondering if these worked even though we don't have the cold weather pack. I'll have to get one of these IR cameras - I do have one, but it's a photographic visible spectrum one

 

[MrBadger]

The door handles will give a massive error on a FLIR camera, due to the very low emissivity of the chrome surface. If the FLIR is the same as my Seek Thermal camera, then it will be calibrated for an emissivity of about 0.9, as this matches most non-shiny stuff.

There are different settings in the FLIR - I just used the standard matte recommended as it was too cold to go calibrating everything and I wanted to get as much in whilst there were big temperature deltas - hence reason why I blurred out the temperature readings too. I'm also not an expert to know what the limits of each setting is - I just wanted the colour spectrum.

 

[MrBadger]

Would these pics of the roof be enough to get it re-seated at a service center? Given both the IR and melting patterns there is obviously a problem there!

Well its going in tomorrow so I hope I get an opportunity to discuss with them. I've already got a hole in headlining in same section so maybe they can look at it then - I was just going to live with the hole, but this makes it a bit more interesting. At end of the day, I have a rubber seal that I will put around when all work is complete - just waiting for all outstanding snags to be done. At moment, the car does not feel ours.

Also did a few leakage check around house - its the right time of year

 

[Glan gluaisne]

There are different settings in the FLIR - I just used the standard matte recommended as it was too cold to go calibrating everything and I wanted to get as much in whilst there were big temperature deltas - hence reason why I blurred out the temperature readings too. I'm also not an expert to know what the limits of each setting is - I just wanted the colour spectrum.

The snag is that the false colour image will be in error by the same amount as the emissivity variation. The chrome handles will look "warm", because they have a very low emissivity (~0.058), whereas the car bodywork and glass will look "cold" because the emissivity will be ~0.93 for the glass and ~0.96 for the paintwork.

The image below is of some glazing with rectangular bits of solar reflective film stuck on to the glass either side of the glazed door:

They look a lot warmer than the glass above and below, or the glass in the door, yet all are at pretty much exactly the same temperature. The warmer appearance of these patches is just because they have a much lower emissivity, very like the chrome handles on the car image.

 

[MrBadger]

And a possible air leak around the roof glass - IR detected it before it thawed

Now a future service item. Gap in seal - roof out which will probably break so new roof to be ordered in.

 

[vitesse]

Interestingly, my two after-market cameras (front and rear) radiate enough heat to keep the frost at bay They are on all the time but frame rate reduces when the car is stationary for a few minutes (parked).