Product overview: Fluke Calibration 4180/4181 Precision IR Calibrators

The 4180 Series of Precision InfraredCalibrators for infrared thermometers and thermal imagers is fast, accurate, and easy to use. It comes with an accredited calibration from one of the world’s most trusted temperature calibration laboratories, sample calibration procedures for Fluke thermometers built right in and everything you need to get started making high-quality infrared thermometer calibrations. This is the perfect solution for any infrared thermometer or thermal imager within its temperature range.

The 4180 Infrared Temperature Calibrator reaches temperatures from –15 °C to 120 °C and the 4181 Infrared Temperature Calibrator has a temperature range from 35 °C to 500 °C. Uniformity is important in infrared temperature calibration work because an infrared thermometer will “see” as much as the entire target when placed at the appropriate calibration distance.

In addition, with accuracies as good as ± 0.35 °C the 4180 Series can meet its specifications without additional emissivity-related corrections, leading to legitimate test uncertainty ratios (TUR) as good as 4:1.

Emissivity, blackbodies and graybodies

Most people associate a blackbody calibration source with calibrating infrared thermometers. Although the word blackbody specifically refers to an ideal surface that emits and absorbs electromagnetic radiation with the maximum amount of power possible at a given temperature, many calibrators with non-ideal surfaces are also referred to as "blackbody calibrators." While an ideal surface would have an emissivity equal to 1.00, many of these "blackbody calibrators" have an emissivity of approximately 0.95 (better described as a “graybody”). A true blackbody calibration source would usually be a long cavity with a narrow opening. Unfortunately the opening is usually too narrow to be useful for calibrating common infrared thermometers which require a large target size for an accurate calibration. The advantage of a true blackbody calibration source is that the emissivity is precisely known. Whereas traditional flat plate calibrators have emissivities with uncertainties too large for meaningful calibrations of most thermometers. That is why the 418X Precision Infrared Thermometers are radiometrically calibrated to correct for uncertainties caused by emissivity and heat loss at the surface of the "blackbody" calibration source.