Define Instrument for Measurement of Absorbed Radiation?
a) Photometer: This is an instrument which it designed to measure the intensity of the beam of light and usually does so by comparing it to the intensity of some reference source of radiation.
b) Spectrometer: This is an instrument which is capable of splitting the incident radiation into a spectrum used to identify the individual wavelengths which are present.
c) Spectrophotometer: This is an instrument which combines both these functions.