FISO Nortech Energy Product Catalog
The measurement principle is based on white light absorption/transmission by a GaAs (gallium arsenide) semiconductor. The effects of temperature variations on this semiconductor are well known and predictable. As the temperature of the semiconductor changes, the semiconductor’s transmission spectrum (i.e. the light that is not absorbed) shifts also. At any given temperature there will be a wavelength at which the transmission jumps from essentially 0% to 100% . This jump is called the absorption shift, and the relationship between the specific wavelength where the absorption shift takes place and temperature is predictable.