Nutrients are essential for life in the water and on land. But too much nutrients (Eutrophication) is harmful. Important nutrients include the nitrogen compounds nitrate (NO3-), nitrite (NO2-), ammonia (NH3) and ammonium (NH4+). Sometimes it is important to measure it separately, but sometimes the total nitrogen (Total-N) is important. Another important nutrient is phosphate (short for orthophosphate, PO43−). Instead of specifically measuring phosphate, sometimes the total phosphorus (Total-P) is important.
Some of the nutrients mentioned can be measured with so-called ISE (Ion Selective Electrode) sensors, see the ‘multiparameter measuring sondes’ category . The advantage of these sensors is that they can be used relatively cheaply and quickly. However, because the calibration expires in short span of time, these sensors need to be calibrated frequently and are therefore mainly suitable for hand measurements and for detecting ‘incidents’ (short-term disturbances) and less for continuously measuring and determining trends.
Accurate measurement of nutrients is very important, but requires high-quality measuring equipment. For that purpose Observator offers instruments from Xylem/YSI, Systea and TriOS: