Moisture measurements – online, real-time, contact-free

The measurement of moisture is the most popular application of our customers.

Our NIR photometers are able to measure the water content of most materials!
We configure each photometer specifically for its measurement task in your process analysis.


Our photometers

  • measure online and in real-time;
  • measure without contact to the product;
  • can be integrated into existing production lines;
  • are low-maintenance and easy to calibrate;
  • provide an output signal for process control and monitoring.


Moisture of transparent materials
The transmission photometer TMK-550 If you need to analyze transparent materials – such as liquids and gases – the most suitable photometer is a transmission photometer. Light is sent through the product sample. The moisture in the product blocks parts of the light at certain wavelengths. The photometer detects those changes and converts them into a calibrated moisture value.

Moisture of opaque materials
The reflection photometer RMK For moisture measurements of opaque materials – such as solids or grains – we recommend a reflection photometer. Light is sent on the product sample. The moisture in the product affects the reflectivity of the product at certain wavelengths. The photometer detects those changes in the reflected light and converts them into a calibrated moisture value.

Moisture of semi-transparent layers
PVB layer analyser RMK-9TTransmission and reflection can be combined to increase sensitivity. The most common example is the moisture measurement of PVB layers for the safety glass of car windshields with our PVB layer analyser.
The light is sent through the PVB and falls onto a mirror which reflects it and sends it through the PVB layer once more.



How does it work?
Basically, we exploit the specific properties of water molecules. Water molecules possess many physical degrees of freedom (in terms of rotations and oscillations of the atoms within the molecule). That leads to a multitude of absorption lines and bands in the near-infrared spectrum. The near infrared (NIR) is the spectral range directly adjacent to visible light (with slightly longer wavelengths of 700 to 2500 nanometers). Common incadescent lamps produce not only visible light, but also usable levels of near-infrared light and can be used as a light source for this type of photometric moisture analysis.