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  1. #1
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    thermal cameras for setup/trouble shooting?



    I watch a few refrigeration guys on youtube sometimes, nice to see how other people do things etc.

    one guy (seams like he knows what he's doing) uses a thermal imaging camera sometimes

    checks for temp drop over filter driers, temp difference across a condenser and checks the liquid level in the receiver


    seamed like a good idea to me so I bought myself one


    giving it a go out of the box I thought I'd check the liquid level in a few receivers... but mine all read the same temperature top to bottom


    what's going on? what's the difference here? I wasn't expecting much of a temp difference, part of me thinks it should all be at ambient temp but maybe fluctuations in the level change the temp of the gas in the top of it?

    any ideas anyone? anyone else use one?

    no idea why it works on youtube but not for me

    maybe hotter countries with higher ambient temp? I (should) have solid liquid feed to receiver, where in higher ambient there might have bubbles in it?



  2. #2
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    Re: thermal cameras for setup/trouble shooting?

    Good for electrical panel checks.
    Is it just a receiver on a commercial unit the youtuber is checking or industrial?
    Maybe the tuber is catching the condenser fan cycling?
    You might be able to fire some discharge gas into the top of the receiver to show where the cool liquid level is.
    Last edited by seanf; 17-09-2022 at 06:12 PM.

  3. #3
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    Re: thermal cameras for setup/trouble shooting?

    That's an interesting question! I'm not sure what could be causing the discrepancy, but it's definitely worth exploring further. Have you tried calibrating your thermal imaging camera? That might help to figure out what's going on. It could also be related to the ambient temperature in your area and how it's affecting the liquid level in the receiver. I'd be interested to hear what others have to say about this!
    Last edited by frank; 27-10-2023 at 03:41 PM. Reason: Adverts removed

  4. #4
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    Re: thermal cameras for setup/trouble shooting?

    You receiver is at the same condensing, saturated temperature, even the gas on top of the liquid, so you can't see the difference. Point once you IR to the condenser bends, you will see the discharge or total SH, condensing and subcooling.
    It's better to keep your mouth shut and give the impression that you're stupid than to open it and remove all doubt.

  5. #5
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    Re: thermal cameras for setup/trouble shooting?

    You see the level in a liquid reciever but it require some conditions.
    as said by Peter if the system is off, no noncondensables, reciever is at the same température top from bottom.
    You cannot see the level in a bottle of refrigerant after a night at 10°c for example. Store it at 20°C and then you'll see the level after a few time. Same for brine or glycol.
    For an operating reciever, if Tc is 30°c and outside temp is 10 or 40°c in the machine room you'll see your level. idem when fan are cycling or non condensable in.
    you must also avoid a cold or hot pipe in the camera field or the picture contrast will be very low. If you take the picture you can specify a contrast area on the reciever with the software (FLIR in my case) and then level appear.

  6. #6
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    Re: thermal cameras for setup/trouble shooting?

    HeyCriCri, long time not seen and happy to see you again, same for me, too long not present here and happy to be back...
    It's better to keep your mouth shut and give the impression that you're stupid than to open it and remove all doubt.

  7. #7
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    Re: thermal cameras for setup/trouble shooting?

    Hello Peter,
    happy to see you again also.
    I'm now retired for two month, exit the 70000 km/year and so many issues on field.
    Some free time to have some attention to the others. Tech manager was not a ''sinecure''
    Now relax!

  8. #8
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    Re: thermal cameras for setup/trouble shooting?

    An example with 3.5°K subcooling
    Attached Images Attached Images

  9. #9
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    Re: thermal cameras for setup/trouble shooting?

    I understand that you are talking about measuring the liquid level in a refrigeration system or chiller system. To measure liquid levels, the temperature of the system must be controlled to ensure that it is not affected by temperature differences in the room or by hot or cold pipes. If the refrigeration system is working, you can measure the liquid level by checking the collector temperature and comparing it to the liquid temperature in the system. If you want to take pictures to measure liquid levels, you need to use measurement software and specify the contrast area to get accurate results.

  10. #10
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    Re: thermal cameras for setup/trouble shooting?

    I have a Fluke thermal camera that makes images similar to what cricri posted, I've tried to use it to determine liquid levels on HP and LP vessels in operation, and it's neigh to impossible because the resolution isn't high enough.

    I were lucky enough to get to test a FLIR GF320



    Waaaay out of my price range, but it worked so much better than the Fluke.

    With the GF320, I could watch the liquid level in the pilot receiver move up and down (with a delay), the fluke just showed the entire tank to be blue.


    This was many years ago, so there have probably come many new products on the market, but the FLIR did so much better than the fluke IR
    -Cheers-

    Tycho

  11. #11
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    Re: thermal cameras for setup/trouble shooting?

    Hey Knighty!

    If its the same guy on youtube I'm thinking of, he heats the receiver up with a hot air gun/torch etc, then uses the thermal camera, where the liquid is soon cools down but where the vapour is stays warm. He does it to make sure there is enough refrigerant for the winter charge when the head pressure valves will back liquid up in to the condenser to maintain head pressure.

    We have a Flir one thats also a multimeter, handy piece of kit, we found duff valves in one cylinder head on a v4 Frascold where you could see one cylinder wasn't doing much.

    https://www.youtube.com/watch?v=zjQOW7FV7sQ
    Mostly found in Oxfordshire, UK :)

  12. #12
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    Re: thermal cameras for setup/trouble shooting?

    hi, winter charge, that sounds like the same guy!

    I never did try heating up a receiver... but I'll give it a go :-)

  13. #13
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    Re: thermal cameras for setup/trouble shooting?

    I've seen a few of his video and the commercial air conditioner he works on have some economiser system on them and need a lot of liquid in the receiver. I'm not technical to know but maybe the economiser system makes the temperature difference enough in the receiver to see with a thermal camera.

  14. #14
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    Re: thermal cameras for setup/trouble shooting?

    Observing the liquid level in a receiver depends on specific conditions, as advised by Peter. When the system is powered off, no noncondensable substances are present, and the receiver maintains a uniform temperature from top to bottom, you won't be able to discern the level accurately. For example, trying to gauge the level of refrigerant in a bottle stored at 10°C overnight is challenging. However, if you store it at 20°C, you'll eventually be able to see the level.

    In the case of an operating receiver, with the condensing temperature (Tc) at 30°C and outside temperatures ranging from 10°C to 40°C in the machine room, the liquid level becomes visible. The same applies when fans are cycling or noncondensable substances are present in the system.

    To ensure an effective level assessment, it's important to avoid having a cold or hot pipe within the camera's field of view, as this can lead to poor picture contrast. If you capture an image, you can use software like FLIR to designate a contrast area on the receiver, which will then reveal the liquid level.

  15. #15
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    Re: thermal cameras for setup/trouble shooting?

    Measuring liquid levels in a refrigeration or chiller system requires precise temperature control to mitigate environmental temperature variations or pipe conditions. When the system is operational, you can gauge liquid levels by comparing collector and system liquid temperatures. If you aim to use imagery for measurement, employ specialized software, outlining a contrast area for more precise results.

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