Message Board Thread - "Effect of focusing on temperature measurement"

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Effect of focusing on temperature measurement brian 10/11/2004
I recently had to make a temperature measurement on a large and very homogeneous but inaccessible target at a distance of several meters. One consequence was that I could not focus the camera (FLIR 160M) correctly or was unsure of the focus setting.
My guess is that that should not have a great influence on the average temperature reading.
Am I correct ?
 
Re:Effect of focusing on temperature measurement electricpete 10/11/2004
My thought is that lack of focus causes a blurred image would increase the measurement IFOV. If it is a large target all the same temperature, this loss of spatial resolution would not make a big difference.

But I would like to hear someone else's thoughts.
 
Re:Effect of focusing on temperature measurement Glave 10/11/2004
FYI, Attached is a slide showing the typical effect on temperature measurement of targets not in focus. As can been seen the smaller the target or the "farther" out of focus it is the more chance for error.
 
Re:Effect of focusing on temperature measurement rickb 11/3/2004
Try placing a box area around the object you want to image, and watch the maximum temperature in that box as you focus. When the maximum temperature falls on the smallest number of pixels, then the camera will be in focus. When out of focus, those pixels will be averaged (a.k.a., 'blurred') with adjacent, cooler, pixels, reducing the maximum reading -- as shown in the previous posting. This technique has worked well on flat objects with large temperature variations, such as heater surfaces.

 
Re:Effect of focusing on temperature measurement nikreila 11/6/2004
focusing. it is a rule of thumb in thermography. if the image is out of focus, the readings are erroneous. also produces a wrong temperature gradient on a line tool for analysis.
 
Re:Effect of focusing on temperature measurement PKS 1/9/2005
I agree with Mr. Nikreila. From my experience it has been observed that Focus plays an important role. If a image is not correctly focused, it will give you less reading.
 
Re:Effect of focusing on temperature measurement Manuel 1/9/2005
yes.. focus it is important..

but besides FOcus, Range and Distant are also important. From Level I:Remember FO_R_D ??..

regards.

roberto cruz
thermoimagen
 
Re:Effect of focusing on temperature measurement RADIO 4/11/2005
If you find it dificult to focus on a target a few meters away, try placing an object of definte size shape such as coin next to the target, now focus on the coin. Next fine tune your focus on your intended target.
 
Re:Effect of focusing on temperature measurement andy_1208 4/12/2005
There is no doubt that focusing is important.We can have an example to certify this.
You will find you cannot see somethings distinct when you take off your short-light glasses,If you always wear a short-light glasses.
I think they are same.
 


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