The impurities measured are at the atomic level within the crystal lattice of carbon atoms and so, unlike inclusions, require an infrared spectrometer to detect.

It was completed several years later, and for a time was known as the most powerful prism infrared spectrometer.

The spacecraft instrumentation includes a framing camera, a visual and infrared spectrometer, and a gamma-ray and neutron detector.

To achieve this, the instrument combined a telescope with an infrared spectrometer.

For this reason far infrared spectrometers have to be freed of atmospheric water vapour either by purging with a dry gas or by evacuation.