Question
What is the difference between a colorimeter and a spectrophotometer?
Summary
Difference between a colorimeter and spectrophotometer.
Answer
Colorimeters (also referred to as Filter Photometers) and Spectrophotometers both measure sample absorbance to determine analyte concentrations.
Colorimeters are usually portable and use LED light sources and color filters. As a result, they operate at fixed wavelengths and can only accommodate tests that incorporate those wavelengths.
Spectrophotometers are usually bench top instruments and use light sources that can produce a range of wavelengths. The spectrophotometers used by Hach use tungsten (or xenon) lamps to produce light in the visible spectrum and deuterium lamps to produce UV light. Spectrophotometers also use monochromators to select for a desired wavelength. As a result, spectrophotometers can be used for a broad range of tests.
The following table highlights the differences between Colorimeters and Spectrophotometers:
Colorimeters are usually portable and use LED light sources and color filters. As a result, they operate at fixed wavelengths and can only accommodate tests that incorporate those wavelengths.
Spectrophotometers are usually bench top instruments and use light sources that can produce a range of wavelengths. The spectrophotometers used by Hach use tungsten (or xenon) lamps to produce light in the visible spectrum and deuterium lamps to produce UV light. Spectrophotometers also use monochromators to select for a desired wavelength. As a result, spectrophotometers can be used for a broad range of tests.
The following table highlights the differences between Colorimeters and Spectrophotometers:
| Colorimeter (Filter Photometer) | Spectrophotometer |
|
| Light Source | LED, Fixed Wavelength | Lamp (Tungsten, Xenon, Deuterium), Wavelength Range |
| Wavelength Selector | Color Filter, Fixed Wavelength | Monochromator, Wavelength Range |
| Portability | Stationary parts, light weight, good for field use | Moving parts, heavier, good for bench use. The DR 1900 can be used in the field. It is lighter and battery operated, but still has some moving parts. |
| Parameters | Single or Limited Number of Parameters determined by Fixed Wavelengths | Numerous Parameters determined by the Wavelength Range. |