It is a device which is used in laboratories for quantitative analysis of specific substances in human body fluids that have capability to absorb light in visible region.
Photoelectric colorimeter uses a photocell, color filters, amplifiers and current detector.
This device is used to measure the concentration of specific substance in subject solution. It is based on 2 very important laws, Beer’s law and Lambert’s law;
> Beer’s law: It states that when a monochromatic ray of light passes through a color solution, its intensity decreases with respect to the concentration of the solution (the more color concentration, lesser the intensity)
> Lambert’s law: It states that when a monochromatic ray of light passes through a color solution, its intensity decreases with respect to the length of the solution.
Principle of Photoelectric Colorimeter:
When light comes from a light source, a filter for specific wavelength is placed in its way to get a monochromatic light. This monochromatic light then passes through the solution sample inside the test tube, after which the intensity of light decreases. It then falls on the photocell which is in turn connected to a detector (e.g.; Galvanometer). The reading gives us the optic density of the solution in the test tube.
This device is widely used in laboratories for analysis of different constituents in the urine etc.
