Editing Infrared Space Observatory (section)

== Instruments ==

ISO carried an array of four scientific instruments for observations in the infrared:
* '''Infrared Camera (ISOCAM)''' – A [[Image resolution|high-resolution]] camera covering 2.5 to 17 micrometre wavelength with two different [[Sensor|detectors]]. Like a visible-light camera it takes pictures of astronomical objects, but the image shows what the object looks like in infrared light.
* '''Photo-polarimeter (ISOPHOT)''' – An instrument designed to measure the [[Polarimetry|polarisation]] of infrared radiation emitted from an astronomical object. The very broad wavelength range from 2.4 to 240 micrometre allowed this instrument to see the infrared emissions of even the coldest astronomical objects such as [[Interstellar cloud|interstellar]] [[Cosmic dust|dust clouds]]
* '''Short Wave Spectrometer (SWS)''' – A [[spectrometer]] covering the 2.4 to 45 micrometre wavelength. Observations with this instrument provided valuable information about the [[Chemistry|chemical composition]], density and temperature of the universe.
* '''Long Wave Spectrometer (LWS)''' – A spectrometer covering the 45 to 196.8 micrometre wavelength. 

All four instruments were mounted directly behind the primary mirror of the telescope, in a circular arrangement,  with each instrument taking up an 80 [[Degree (angle)|degree]] segment of the cylindrical space. The field of view for each instrument was offset to the central axis of the telescope's field of view. This means that every instrument 'saw' a different portion of the sky at a given moment. In standard operational mode one instrument was in primary operation.