An optical instrument used to measure properties of light over a specific portion of the electromagnetic spectrum, typically used in spectroscopic analysis to identify materials. The variable measured is most often the light's intensity but could also, for instance, be the polarization state. Often used in astronomy and some branches of chemistry.Electrostatic spectrometer in wooden box. Measured in Kilovolts.Serial number 108 MCCES 1942 FGspectrometer, scientific instrument, electromagnetic spectrum, light's intensity, astronomy, optical instrument