Blackbody Truths: Uncertainty

Entrance aperture of a windowless Brookley blackbody furnace at 2000 degrees C

Entrance aperture of a windowless graphite tube blackbody furnace at 2000 °C.

Blackbody thermal radiation sources seem to be everywhere; you can even buy them over the Internet. Some are precision one, some are most definitely not! How do you know what specifications are necessary to fit your needs?

Some specs are really simple, if you think about it for a while. To verify an instrument's calibration or to calibrate it, the temperature uncertainty of the reference source (the blackbody) should be, as a minimum, one fourth that that of the device you are checking. Some metrologists insist that it be one tenth. This is fundamental and can help you speed your search by eliminating units that fail to meet this simple norm.

If you are checking device calibration with a nominal measurement uncertainty of 1% you then need a blackbody source with an uncertainty of between 0.1% and 0.25%. So, first thing to check when considering a blackbody is its uncertainty specification. Be sure you get one with enough precision. That's why we only make precision blackbodies. Check this link for some more information on blackbody calibrators.

1. Blackbody Precision

2. Blackbody Traceable?

Precision Blackbodies

A laboratory blackbody approximates Max Planck's ideal. We strive to provide the closest approximation that a reasonable budget and the needs for precise sources of blackbody thermal radiation can provide. It is easy to get it wrong. Don't be afraid to ask advice.

Copyright 2003 Thermo Gauge Instruments, Inc. , All rights reserved