Photometry is a branch of science that deals with the measurement of light in terms of its perceived brightness to the human eye. It is concerned with quantifying the amount of light that is emitted, transmitted, or received by an object or a system. A colorimeter is an instrument that compares the amount of light getting through a solution with the amount that can get through a sample of pure solvent. A colorimeter contains a photocell which is able to detect the amount of light passing through the solution under investigation.
