Black Body Calibrators - Nagman Instruments

      Black body calibration sources from Nagman permits the calibration of infrared temperature sensors with low uncertainty. This editorial elaborates on what makes the most excellent black body calibration source for a specified function and what you should judge when selecting one.

   A black body calibration source is a tool for examining the calibration of an infrared temperature sensor. It consists of a heated or cooled target object whose temperature is accurately known and is the foundation for accurate calibration of infrared pyrometers.

     The black body calibrators are a perfect radiator i.e. it emits thermal energy whose power at a given wavelength and temperature follows Planck’s Law of radiation. It absorbs and emits all radiation and has an emissivity rate of 1.

   Since there no matter exists that could make a true perfect black body, in practice, a black body calibration source for all time has a slightly lower emissivity than 1, nevertheless by cautious design it is probable to get very close.

    The emissivity setting of the sensor ought to be adjusted to go with the emissivity of the black body; in addition to that, the sensor has to be mounted secure enough that the calculated spot diameter is no greater than half the aperture diameter.

Nagman offers a range of black bodies for different applications:

    For very precise calibration checks, the BB976 and BB982 black body sources provide the maximum performance. These models are preferably situated in a calibration room or laboratory where a steady ambient temperature allows you to take full benefit of their performance, even though the built-in carrying grip does permit them to be moved around the site if necessary.

     The two models are at variance in their temperature range. Both have exceptional steadiness (±0.1°C) and a built-in temperature meter with high resolution (0.01°C). They are abounding with a PC interface, software and a 3-point traceable calibration certificate.

   These black bodies withhold of a temperature-controlled cylindrical thermal cavity which has a tiny aperture at one end. We can give elective orifice plates which limit the cavity aperture more. This can be obliging when calibrating thermal images.

   A heating slab heats the thermal cavity to the heat selected on the en suite controller. Cooling essentials in the BB982 allow the unit to reach temperatures under ambient. The infrared radiation emitted as of the cavity can then be used to calibrate a non-contact temperature sensor whose field of observation is aimed through the center of the aperture. A separate fitted temperature indicator and platinum confrontation contact thermometer offer a precise reference measurement of the cavity temperature.

   Radiometric calibration of these black bodies is accessible, as is the calibration of the platinum resistance thermometer.