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This article discusses two types of analysers to measure nutrients: a wet chemical analyser and an optical nitrate analyser. A nutrient analyser is an example of an oceanographic instrument to measure the concentration of certain nutrients (e.g. nitrate, nitrite, ammonia, phosphate and silicate) in situ.
Nutrient analysers are oceanographic instruments to measure the concentration of certain nutrients in situ. While most measurements of nutrients are still made by taking water samples for later analysis in the lab a variety of in situ instruments has become available that automatically measure nutrient concentrations at pre-programmed intervals. These instruments allow a much higher temporal resolution of measurements than what can be achieved by taking samples.
Most of the nutrient analysers are based on proven wet-chemical laboratory analysis methods. In recent years nitrate analysers based on the absorbance of ultraviolet light by nitrate in water have been introduced. Both are discussed in this article.