Message Board Thread - "Measuring exact temperatures with different emmissivities on IR sensor and Heat Source"

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Measuring exact temperatures with different emmissivities on IR sensor and Heat Source Uzair 5/22/2005
How can we measure exact temp while scanner emmissivity is set at 0.95 and the heat source emmissivity is 0.99. Can anybody help?
 
Re:Measuring exact temperatures with different emmissivities on IR sensor and Heat Source Gary Orlove 5/24/2005
Try this to get an approximate correct temperature reading.

Correct temperature reading = (Incorrect reading – Treflected)* (0.95/0.99) + Treflected

Where:
Correct temperature reading is your desired true temperature with emissivity at 0.99
Incorrect reading is the reading you get with emissivity set at 0.95
Treflect is the reflected apparent temperature of the surroundings that has been set in the instrument

Gary Orlove
Infrared Training Center
 
Re:Measuring exact temperatures with different emmissivities on IR sensor and Heat Source Uzair 5/31/2005
Thanks for the reply.

There's no setting for Treflected in the temp. controller. Should just subtract the ambient temp.?

Also, do you know if the results would be within a certain percentage of being accurate?
 
Re:Measuring exact temperatures with different emmissivities on IR sensor and Heat Source johanw 6/2/2005
Uzair,

my estimation is in the added picture.
The assumed conditions are also in the picture.
Your temp. indication is too high, but that's what you've found out already, I assume.
Success.


 
Re:Measuring exact temperatures with different emmissivities on IR sensor and Heat Source Gary Orlove 6/2/2005
Yes, try subtracting the ambient temperature then.

Gary Orlove
Infrared Training Center
 
Re:Measuring exact temperatures with different emmissivities on IR sensor and Heat Source johanw 6/3/2005
In my calculation I assumed an environment temperature of 20o C. You can see it because the line e=1 crosses the 0-deviation when the object temperature is also 20o C. The wavelength of the pyrometer (or camera/scanner) is assumed to be long wave ic. 10 micron.

Johan Wullink
The Netherlands.
 


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