“Short” Wavelength Applications Advantage

Concord,MA, USA — As seen on the Williamson IR website:

“Single wavelength infrared thermometers filtered in the short wavelength region of 2.0 to 2.5 microns offer good performance when measuring low emissivity materials at low temperatures.”

“The accuracy improvement associated with the shorter wavelength sensor is shown in the figure below. The shorter wavelength sensor shows an improvement in measurement from about 18°F (10°C) to about 5°F (2.8°C) when measuring a 220°F (104°C) target with a 10% variation in emissivity. This alone does not explain the total improvement in accuracy achieved by the component supplier. The short wavelength measurement also benefits from the fact that most metals have a higher emissivity value at the shorter wavelength. Therefore, considering these two benefits the shorter wavelength sensor offers as much as ten times more accurate readings than is a long wavelength sensor.”

{Image: Courtesy Williamson Corporation}

Read the rest of an actual case story at www.williamsonir.com/page.php/id/233

ED NOTE: The terms “Short Wavelength” , “low emissivity” and “low temperature” are relative, of course and here they are used in the context of a measurement in the 150 to 1000°F temperature region of unoxidized metal surfaces. They should not be confused with the similar terms used in the field of telecoms, particularly on the terms used when referring to mobile phone signal emission.