Colorimeter (chemistry)

As a colorimeter ( Lat. color meter ) is a device for measuring or comparing colors called (actually the color intensities or color temperature). The easiest way is the direct subjective comparison of the sample with reference color maps using the human eye. However, more complex optical devices more reliable, in which one similarly viewed as a stereoscopic microscope with an eye, the test object and the other, the reference object. Such devices have been used since 1850. This report uses either solid color Normal or mutable reference objects such as color wedges ( Pulfrich photometer, after Carl Pulfrich ), or colored liquids with changeable thickness ( Eintauchkolorimeter ).

The objective color measurement is usually done using a spectral analysis. To the incident light is split into different spectral ranges and the intensity distribution examined. Today's devices are not limited to visible light, but can be used for special tasks in the infrared or ultraviolet light to make measurements.

Colorimeters are used eg for

• Determination of star colors ( earlier)
• Analysis of biological substances ( such as blood sugar or urine)
• Calibration of color monitors

And the

• Analysis of chemical substances: by means of this measurement system are virtually all chemical methods of analysis in the laboratory using a colorimetric method, also suitable for a quantitative and automated material analysis. For this purpose, many different instruments have been developed and used in practice with success. As an example, water and wastewater engineering is given. Here the carbonate hardness, total hardness, silica (SiO2) are often - and the phosphate content monitored in the water with such instruments.