Thermal camera ?

[sarabande]

I have a number of probable uses for a thermal imaging camera in the hydro station, the boat, and the saw mill.

There are multiple cameras and formats available on Amazon.

Best to buy a separate IR camera, a phone with built-in IR, or a supplementary device which plugs into the phone, please ?

All advice welcomed.

 

[Refueler]

Pal of mine just bought a Thermo camera of AliExpress ... just asked him which one .. and what he thinks of it. I know he's checking out his house and where heat is leaking out !!

mileseey tr256b

Reckons its quite good ... Ok - not professional quality ..

 

[lustyd]

I used to have the Flir One which was excellent and saved me a fortune through checking my house over. Doors, windows and insultation all sorted which made the house warmer and more comfortable. It can give you temp readings anywhere on the image.
It plugs into a phone which is great but beware that iPhone are changing to USB-C

 

[Rappey]

Seek thermal, a tiny camera that plugs into your phone and uses phone screen. For the money they have better resolution than the competition.
A phone with built in will go out of date , keeps you tied into that phone. A stand alone depending on what you spend has a tiny screen.
A phone plug in can be used with each new phone you buy.
Make sure your buying a true thermal imager and not an infra red claiming to be a thermal image.
I've had my seek around 5 years and still love it.

 

[Refueler]

I used to have the Flir One which was excellent and saved me a fortune through checking my house over. Doors, windows and insultation all sorted which made the house warmer and more comfortable. It can give you temp readings anywhere on the image.
It plugs into a phone which is great but beware that iPhone are changing to USB-C

Blimey - you say that iPhone are actually joining us mere mortals ???

 

[bikedaft]

Seek thermal, a tiny camera that plugs into your phone and uses phone screen. For the money they have better resolution than the competition.
A phone with built in will go out of date , keeps you tied into that phone. A stand alone depending on what you spend has a tiny screen.
A phone plug in can be used with each new phone you buy.
Make sure your buying a true thermal imager and not an infra red claiming to be a thermal image.
I've had my seek around 5 years and still love it.

puzzled by your comment re difference between thermal imager and infra red? i always thought that they were the same thing?

FLIR - forward looking infra red (Police/Coastguard etc). I have played with it on the ground - great

 

[Refueler]

Seek thermal, a tiny camera that plugs into your phone and uses phone screen. For the money they have better resolution than the competition.
A phone with built in will go out of date , keeps you tied into that phone. A stand alone depending on what you spend has a tiny screen.
A phone plug in can be used with each new phone you buy.
Make sure your buying a true thermal imager and not an infra red claiming to be a thermal image.
I've had my seek around 5 years and still love it.

Sadly I have various gear that plugs into phone or tablet ... that no longer work as Android has updated to new version as I change phones and the gear only wants older version.

I have a very good endoscope - its OTG - BUT will not work with my later phones or tablets - I have to use an old tablet ... so much so that I have bought a new Endo that uses WiFi instead .. I don't really need the UHD that my old one had. HD is good enough.

 

[ctva]

Not cheap at £250+ for the simple phone units.

What makes them so expensive for what is probably a simple item? Unless of course it is not simple.

 

[kwb78]

What makes them so expensive for what is probably a simple item? Unless of course it is not simple.

They use a completely different operating principle to a visible light camera, and the market is tiny in comparison. To get any capable thermal imager at that price point is remarkably cheap in comparison to what they have been historically.

The various Chinese models that use the Infiray Tiny1-C thermal core are probably a better bet than the low end Flir cameras or Seek. Those are saddled with US ITAR regulations which restrict frame rates to 9Hz and they are generally lower resolution. The Infiray core has a resolution of 256x192, and 25Hz frame rate. This is high enough to tell what you are taking an image of without having to resort to overlaying an outline from a visible camera (which is what the cheaper Flir cameras do). For example, the Flir One has a resolution of 80x60 thermal pixels, and a sensitivity of 150mK (that is the smallest temperature difference it can perceive). The Infiray core has a resolution of 256x192, and a sensitivity of 50mK. This may sound low compared to a visible light camera, but for a thermal imager it's quite good. Higher resolutions are available but can be very costly.

The Flir One costs about £230, and you can get various models using the Infiray core from about £120 upwards depending on where you look.

It's not all one way however, and there are some advantages of the Flir device - the software is better developed and if you want to use it for anything formal or need to take accurate measurements then it might be a better bet.

It's worth looking into a bit before you choose what to get as there are quite a few options that are similar. There are handheld stand alone units for not much more with similar capabilities if a phone dongle isn't ideal.

I have a Tooltop T256 (actually manufactured by Dianyang Technology) which uses the Infiray core and am quite happy with it. It's easy to see things like faults with window seals, damp, missing insulation etc. It's also useful for fault finding electrical items. You won't be filming nature documentaries with it, but it's good enough for casual use. It cost about £110 from Aliexpress and plugs into the USB-C on the phone. It can also be connected to a PC and there is various software available to use with it.

Here are some example images.

This shows the effect of a cold air draught coming from under a cupboard door where the draught excluder isn't placed properly:



This shows the effect of failed silicone sealing under an exterior door frame allowing cold air in:



This is an external wall where the house has been extended, but the insulation isn't great. You can see the blockwork structure and placement of the steel support beam. The hotspot on the left is a couple of DC power supplies for electronics - these aren't noticeably hot to the touch, but show up clearly. You can also see the stream of warm air from a radiator out of shot hitting the ceiling:



Here's an example of missing insulation compared with the adjacent section which is insulated. This section of ceiling is where there is a sloping roof close above it so there is a narrow gap that is hard to get to, and whoever did it hasn't bothered to get in to cover it. The brighter blobs in the dark blue patches on the right are where birds got access behind the soffit and built a nest. You can easily see the ceiling joists in both areas which have a different thermal conductivity:



This is a video clip of me touching a worktop for a fraction of a second, and the visible heat transfer from such a brief contact:

thermal-hand

This is me opening a thermostatic radiator valve slightly to cause the radiator to heat up. I sped it up a bit because it would be a bit long otherwise. Yes my hand is cold because I'd just been outside doing something.

Radiator

 

[Keith-i]

I have a professional grade FLIR handheld unit which was about £4k some years ago. The advantage is that you can change the lens on the front to alter the field of view. It has a built in screen but can also wifi images on to a phone so best of both worlds. For home interest and occasional use I’d probably go for the FLIR lens that clips onto my iPhone for convenience. As noted they are all quite low resolution compared to visible light cameras.

 

[Refueler]

Here's the recordede image from my pal's AliExpress Thermo Camera I mentioned earlier :

 

[sarabande]

Thanks everyone for the contributions of technical knowledge and personal experience.

I shall look at the "addon" units rather than one "built in" to a phone. Really pleased with the information.

 

[trbt]

Not cheap at £250+ for the simple phone units.

What makes them so expensive for what is probably a simple item? Unless of course it is not simple.

They are nothing like regular visible light cameras or "infrared" cameras (like e.g. trail cameras). Google "microbolometer" to learn about the operating principle.
I have an Infiray P2 Pro (from eleshop.eu) and find it quite good for casual interests like finding insulation problems in the house or with optional macro lens also electronics troubleshooting, but I have no experience with anything other.

 

[trbt]

I have a very good endoscope - its OTG - BUT will not work with my later phones or tablets - I have to use an old tablet ... so much so that I have bought a new Endo that uses WiFi instead .. I don't really need the UHD that my old one had. HD is good enough.

WiFi is no answer, if the vendor software is just no longer updated and the thing is something non-standard. I have a WiFi endoscope and one day the app just stopped working after some android update. After trying many other apps that all claimed to work with endoscopes but didn't with mine, I was finally able to find one that recognized the endoscope. The software side of these cheap chinese things is a real mess.

 

[kwb78]

puzzled by your comment re difference between thermal imager and infra red? i always thought that they were the same thing?

There are different wavelengths of infrared light. You can get infrared cameras which see near-infrared in the range 0.75-1.5µm and shortwave infrared in the range 1.4-3µm, and these work more like visible light cameras, from reflected light. They are what your TV IR remote control uses, and some security cameras which can be seen with IR floodlights. Sometimes mobile phone cameras can see the LED of a remote flickering if their IR filter is not particularly strong.

Thermal imagers use long wave 8-15µm IR and directly detect the infrared radiation given off by objects. The way they build an image is different to a digital visible light camera. With visible light photography, light from some source like the sun or a lamp is reflected off an object, and is focused onto a sensor. The photon hitting the sensor generates an electric charge which can be read to determine how bright each pixel should be. More light on a pixel means more charge and a brighter pixel. They can only work when there is some light source being reflected, since most objects are not hot enough to emit visible light themselves. It's only when things get really hot that you can see them glowing.

A thermal camera works differently - everything above absolute zero emits long wave infrared radiation. The hotter it is, the more is emitted. By focusing that IR light onto a pixel which consists of a tiny piece of material which is suspended in a vacuum, the infrared light heats the pixel, slightly changing its resistance. The change in resistance can be measured and used to determine a brightness for that pixel. Because they can detect radiation directly emitted from objects, they can form an image even when there is no external light source which is why they are used as night vision devices.

It's a lot harder to create an array of these physical structures than it is to make an array of photodiodes which make up a visible light sensor, which is why thermal cameras tend to be a lot lower resolution and a lot more expensive to make. There are other methods to make an infrared imager but they tend to be even more expensive than the microbolometer type used in this sort of lower cost device.

 

[Refueler]

WiFi is no answer, if the vendor software is just no longer updated and the thing is something non-standard. I have a WiFi endoscope and one day the app just stopped working after some android update. After trying many other apps that all claimed to work with endoscopes but didn't with mine, I was finally able to find one that recognized the endoscope. The software side of these cheap chinese things is a real mess.

Correct on many ....

Latest Endo I have uses the generic Go system ...