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Products for high-precision analysis of ammonium, nitrate, nitrite, phosphate and total phosphorus

Nutrient analyzers and sensors control outlets of wastewater treatment plants to ensure regulatory compliance and minimize discharge fees. They help optimize aeration control and precipitant dosing during biological treatment of wastewater, and monitor denitrification processes to support you in supplying safe drinking water, mineral water and process water.

How to select nutrient analyzers and sensors

Nutrient analyzers and sensors are used in the water and wastewater industry. Their selection depends on the application. Choose in-situ sensors for nitrate and ammonia where fast trend measurement is required to achieve timely and precise process control. Select colorimetric analyzers for ammonia, nitrite, phosphate and total phosphorus when high-precision analysis of critical control points is needed to comply with limit values stipulated by water authorities.

Nutrients analysis with colorimetric analyzers

Reagents are added to the sample to “dye” the nutrient that is being analyzed. The color intensity is then measured photometrically, based on the fact that nutrients absorb light of a specific wave length. The absorption is proportional to the concentration of the dyed nutrient and it is determined using preset calibration curves. Some nutrients are not in the correct chemical form to provide a color reaction, they need to be prepared by adding a digesting reagent at an elevated temperature.


Nutrients analysis with optical sensors

This method is based on the fact that nitrate ions absorb UV light in the range of approximately 190 to 230 nm. The ultraviolet light of a flash lamp is transmitted through the medium. The beam is split and directed to two receivers with filters. One determines the light intensity at the measuring wavelength and one at the reference wavelength. The ratio between the two measurements is used as the measurement result and converted to the concentration of nitrate using a preset calibration curve.



Nutrients analysis with optical sensors

​The heart of the ion-selective electrode is a membrane that is selective for the specific ion to be measured. Ionophores are accommodated in this membrane. They facilitate the selective “migration” of the ions to the inside of the ISE electrodes. This change in charge generates an electrochemical potential. This potential is measured against a reference electrode with a constant potential. It is proportional to the ion concentration and not influenced by the medium's color and turbidity.


  • Our pH sensors and transmitters meet all requirements from basic functionality up to multichannel and multiparameter measurement.

  • We offer pH buffers, pH solutions and pH standards for pH calibration to ultimate precision. They are produced in our own permanent calibration laboratory that has successfully passed the DAkkS accreditation (German accreditation authority).

  • The different types of electrodes cover all kinds of diaphragms and reference systems, from dirt-repellent PTFE junctions over highly sensitive ceramic diaphragms to blocking-resistant open apertures.

  • We offer pH assemblies for all fields of applications: fixed installation assemblies, immersion assemblies, flow assemblies and retractable assemblies.

  • Automated systems for calibration, adjustment and cleaning ensure optimum performance of the pH sensors and transmitters in chemical processes, pharmaceuticals production or hygienic applications.

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