Photometry
The Role of Chlorine Colorimeters in Disinfection
Colorimetry is a way to measure the concentration of substances that absorbs light. In a colorimetric test, a reagent is added to a water sample. If the analyte that a user is trying to detect, like chlorine, is present in that water sample, a color change will occur.  A colorimeter is an instrument used to measure the intensity of that color change and correlates that change to a useful unit of measure for the user– such as mg/l chlorine.
The principle of photometry
When specific reagents are added, the water sample takes on a degree of coloration that is proportional to the concentration of the parameter being measured. The photometer measures this coloration.
Interference filter increases reducibility
Only when interference filters are used is it possible to ensure that their analytical methods are reproducible. All Lovibond LED photometers use high-quality interference filters with a half-width of approx. 5 nm.
Reference beam technology for spectrophotometers
Using reference beam technology, the spectrophotometers achieve maximum accuracy in the visual and non-visual wavelength range. The light source according to the model and consists of a tungsten-halogen lamp in the XD 7000, while the XD 7500 is equipped with a xenon flash lamp.