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Making proper measurements when looking from one atmospherre into another
02-26-2019, 12:00 PM
Post: #1
Making proper measurements when looking from one atmospherre into another
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     .

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     .

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
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02-26-2019, 09:18 PM (This post was last modified: 02-26-2019 09:35 PM by acardoso.)
Post: #2
RE: Making proper measurements when looking from one atmospherre into another
What is the transmissivity of the windows? Just to start.

(02-26-2019 12:00 PM)bbosma Wrote:  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 .

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 .

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
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02-27-2019, 05:00 AM
Post: #3
RE: Making proper measurements when looking from one atmospherre into another
Thank you for your reaction!

(02-26-2019 09:18 PM)acardoso Wrote:  What is the transmissivity of the windows? Just to start.

In case of the first scenario, when there is just an open gap, and two atmospheres collide, I do not know what the tansmissivity of the window is. At such a short distance and temperature, I have found that transmissivity of the atmosphere can be neglected, however, I have found that it apparently can not.

In case of the second scenario, the gap will be covered with either High-Density PolyEthylene (HDPE) or Low-Density PolyEthylene. Both transmissivities I have been able to determine using FTIR. Both can be seen in the added graphs in the range from 7um to 14um.


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03-01-2019, 08:33 AM
Post: #4
RE: Making proper measurements when looking from one atmospherre into another
This will be a lot easier with the first arrangement ( the open gap).

If the distance to the object is short then you should be able to neglect the atmospheric corrections. It is possible that this is not where your error lies.

Please contact me offline on bob”at”thermalvision.ie
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