Frequently Asked Questions

Here you will find a compilation of questions and answers from practice, for practice. If you cannot find the answer to your question or require more detailed information, please contact us. We’re here to help!

Ammonium / Nitrate

The advantages over wet-chemical analyzers are manifold:

  • no reagents
  • no sample preparation
  • almost maintenance free
  • easy installation at the edge of the pool
  • Measurement directly in the medium

Usually less than 2 minutes.

The wear is similar to a DO probe. It is only the membrane head and the electrolyte to change. The cost of a set of wearing parts is usually less than 200 euros per year.

The highest accuracies can be achieved in the range of 1 ~ 1,000 mg/L (ppm). Below 1 mg/L (ppm), the measurement accuracy is limited, but a measurement is easily possible.

  • Pre-treatment process (e. g. for filtrated water management)
  • aeration tank (optimization of oxygen input)
  • outlet of final clarifyer (monitoring of compliance with limit values)

Typically ± 5% of the reading and ± 0.5 mg/L (ppm).

Usually only the probe cleaning and a matrix adjustment. The matrix adjustment can be easily done by a photometric comparison measurement in the laboratory. The laboratory value is entered into the instrument and the meter automatically corrects.

Conventional ion-selective electrodes (ISE) can make a poor distinction between nitrate and chloride. GIMAT has developed a special membrane that made the measurement much less sensitive to chloride.

Chemical Oxygen Demand

All ingredients of wastewater that consume oxygen chemically during oxidation. In addition to carbon compounds, these may also be nitrogen and sulfur compounds.

TOC (Total Organic Carbon) records only the carbon compounds. Other wastewater ingredients that have a COD but no carbon are not detected.

If the water and wastewater composition changes, an exact conversion factor cannot be calculated.

Sometimes good relationships can be established between the SAC (Spectral Absorption Coefficient) and the COD. But with fluctuating wastewater composition, often no good connection can be determined.

The COD value, since the treatment plant is designed after the COD and in the laboratory usually the COD is determined.

The combination of the oxidizing agent H2O2 and UV light as an energy source. This makes the GIMAT method safe for the user, environmentally friendly and at the same time it guarantees a very good digestion of the sample. The H2O2 / UV method is an online method recommended by German guideline DWA 269.

With ozone (O3), but ozone is harmful to the user.

0 ~ 600 mg/L (ppm) without dilution of the sample. When diluting the sample with drinking water, measuring ranges of 100 ~ 10,000 mg/L (ppm) can be achieved.

Phosphate / Phosphorus

This depends on the application. In certain applications, ultrafiltration still proves best.

In certain applications, in particular the pre-treatment process, ultrafiltration continues to be unbeatable.

At the end of primary clarification in order to be able to react as quickly as possible to fluctuations in the phosphate concentration or load. Where a Bio-P degradation takes place, the measuring point should be at the end of the process.