Transmission Rate

We find for most predictive maintenance applications (pdm – electrical) that the absolute transmission rate of the window material is relatively unimportant. However, if you know the transmission of your material you can adjust for it in your camera or software and maintain the stated accuracy of your camera.

The transmission of most materials will vary as you move through the wave lengths. So how do you know what transmission to use? Through testing we have found that for the temperatures most commonly found in electrical and predictive maintenance applications that short wave camera are operating at about 4 micron and long wave at about 9 micron. Know your transmissions at those points!

This graph shows how temperature readings can vary with transmission rates, it shows a change of 11.8 °C between 99% and 50% optical transmission on the same image. Camera Transmissivity Adjustment (along the X Axis) and (Indicated Target Temperature) for the Y Axis
This demonstrates the importance of knowing the transmission rates of the window you are using.