The literature associated with measurements made by MALS photometers is extensive. Instruments included particle detectors of varying types, magnetometers, and photometers for observing auroras. Precision photoelectric photometers can measure starlight around 0.001 magnitude. Photometers for microtiter plates are filter photometers. Two types of photometers are used&colon; spectrophotometer and filter photometer. The instrument utilizes flow cells, photometers and apertures to analyze different elements in the blood. In filter photometers, optical filters are used to give the monochromatic light. Atomic absorption photometers are photometers that measure the light from a very hot flame. Most photometers detect the light with photoresistors, photodiodes or photomultipliers. Some photometers measure light by counting individual photons rather than incoming flux. Photometers are used to determine the correct exposure in photography. Most photometers convert light into an electric current using a photoresistor, photodiode, or photomultiplier.