In analytical chemistry terms the difference between colorimeter and spectrometer

is that colorimeter is an analytic instrument that estimates the concentration of a substance in a sample by measuring its color against the solution's complimentary color while spectrometer is an optical instrument for measuring the absorption of light by chemical substances; typically it will plot a graph of absorption versus wavelength or frequency, and the patterns produced are used to identify the substances present, and their internal structure.

As nouns the difference between colorimeter and spectrometer

is that colorimeter is any of various instruments designed to determine the color of something, by comparison with standard colors or by spectroscopy while spectrometer is an optical instrument for measuring the absorption of light by chemical substances; typically it will plot a graph of absorption versus wavelength or frequency, and the patterns produced are used to identify the substances present, and their internal structure.