Calorimetric detectors
It is a blackbody radiation
detector , usually used to calibrate the spectral response of other detectors.
The calorimetric detector is also a fast-response calorimeter, made in the form
of a conical cavity, with an emissivity and absorption coefficient greater than
0.995 from visible light to 40m. It is one of the standard black meters and can
be used to calibrate the emission energy of other emitters or the absorption
coefficient of detection elements.