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Making proper measurements when looking from one atmospherre into another - Printable Version

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Making proper measurements when looking from one atmospherre into another - bbosma - 02-26-2019 12:02 PM

Hello everyone,


I am running into a problem. I am trying to make measurements of objects (and later children) inside an incubator in which the temperature is higher than the temperature in which the camera will be. The material of the incubator has a very high emissivity in the wavelength range I will be performing my measurements (7-14um), and is thus not suitable to measure through.
On this object (a cardboard box) I have placed a temperature sensor (a thermistor) without coverage.

This creates the situation as seen in [attachment=378].

In this situation, two atmospheres exist who are also in contact with each other, and will combine at the opening of the incubator. I do not know how this happens, as I lack thermodynamics knowledge.

In an attempt to make this situation less complex, I have found material through which the camera is able to measure radiation, which would create the situation as seen in [attachment=379].

Essentially this creates two separated atmospheres.

Now, the problem I have, is that I am not quite sure how to adjust certain parameters, i.e. reflected apparant temperature, atmospheric temperature, etc. for either situation. Using a plethora of different settings, I can not synchronize the camera measurement with the temperature measurement, which is ultimately my goal: make accurate thermographic measurements of the object/child in the incubator.

Would any of you know where I can find any literature on this, or how to solve this problem? I am using a FLIR SC305 using FLIR Quickplot (I sadly no longer have access to IRResearchMax).

With kind regards,

Bas Bosma, a (desperate) master's graduate student


RE: Making proper measurements when looking from one atmospherre into another - bdayyani - 03-22-2019 05:08 PM

Hello Bas,

Well, your question is definitely an intriguing one. What usually happens in industry is that there will be an IR window which can be seen through in infrared, and there will be a group of sensors inside the enclosure. You can have the infrared camera very close to the IR window with a perpendicular angle and take the image. You will need to know these parameters to make a correct measurement of the target structure:
- Emissivity of the target structure ( either measured or estimated )
- Reflected temperature off of the target structure
- Transitivity and surface temperature of the IR window ( which when entered in FLIR Tools, would correct the temperature measurements )
- Atmospheric temperature and relative humidity from inside of the enclosure (which can be obtained by sensors that have been already put in place)

Would this scenario work for you and your application? If so, all these parameters are obtainable hence the corrections can be made. If not, then we gotta dive deep into Stephen-Boltzman law and atmospheric corrections which can be a bit tricky. Understanding that you are a graduate student, we can easily find the solution to this issue one way or another.

Please let me know if this works for you or not.

Babak Dayyani,
Application Developer
QEA Tech


RE: Making proper measurements when looking from one atmospherre into another - Delpino - 05-29-2019 08:35 AM

Would you say a scenario like this is rare, Babak?


RE: Making proper measurements when looking from one atmospherre into another - bdayyani - 09-23-2019 10:29 AM

(05-29-2019 08:35 AM)Delpino Wrote:  Would you say a scenario like this is rare, Babak?
Hi,

I have not seen this scenario in action. Whenever there were two atmospheres, there was some sort of a separator between them. I wouldn't call it rare but it certainly is uncommon.

Regards,
Babak


RE: Making proper measurements when looking from one atmospherre into another - jvoitl - 09-26-2019 10:06 AM

What is the distance you will be shooting through each atmosphere? It seems like shooting into an incubator the distance would be so short as to not affect your readings.