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Contactless measurement of moisture, fat and thickness content


NDC Infrared's equipment measures content of different materials on-line in production without touching or destroying the product. Examples are:

  • Moisture content in paper, food and minerals.
  • Fat and protein content in food.
  • Layer thickness of glues and plastic films in one layer or separate layers in coextruded material.
  • Alcohol content in beer under production.
  • Nicotine and moisture content of tobacco.

The substance in question is detected by infrared light. The gauge looks like a camera and sends a beam of light in a spectrum that is perfectly suited to the substance to be detected. Reflected or transmitted light is analysed and the result will be a quick and reliable reading.

Special solutions for intermittent production are available.


Lab -2-food

Moisture gauge for single tests.


Standard for many industries

NDC Infrared has long experience in the field and are constantly developing new applications. Today, their equipment is something of a standard around the world in areas such as:

  • Food
  • Tobacco manufacturing
  • Rendering industry
  • Paper and board industry

The backbone of the system are the meter MM710e/IG710e configured with optics and filters for the measurement task.

The work of the gauge depends on the application either by reflection or transmission. 

Transmission is used e.g. for measuring the thickness of plastic film, or moisture in the paper at high grammage. This measuring head is divided into two parts. The one sending out the light and the other receiving and analyzing.



On-line measurement of mois-
ture content of a process.


More information

The principle of measurement is based on the light with certain wavelengths in the near infrared region, NIR, puts some substances, such as water molecules, in vibration. The greater proportion of water the moisture carrier contains, the smaller of the emitted light wavelength energy is reflected back to the gauge because of the molecule energy absorbtion.

To minimize the effect of other factors on the energy reflected, for example, variations in particle size, colour and ambient light, reference wavelengths are also sent out and they are chosen so that they are not absorbed by the product molecules.

By comparing the energy of the reflected wavelengths the moisture content / thickness can be determined. A rotating disc and a number of filters in the optical path of the gauge determine the wavelengths of light emitted.

Principle diagram herein shows a typical gauge set up with light transmitters and receivers in the same unit. For moisture measurements on thick paper are also common transmitter and receiver measuring head used but the angle against the surface is slightly less than 90 degrees. For thin IR transparent materiasl such as certain plastic films transmission can be used, i.e. the transmitter on one side and the receiver on the other.

Note the large allowable tolerance in the measurement object height, ± 100 mm. Also note that moisture content of the surface is measured. Mechanical accessories are available for measuring the moisture content inside such thick powder flows.


Emitting at least one reference and
one measuring wavelength makes the
gauge very tolerant to height
variations of the target surface. Distances in millimetres.


Mer information

NDC Infrared's products do not allow themselves to be presented on one page. These systems are often tailored to specific measurements and here we can only give a general idea of their possibilities. Contact Pentronic for more in-depth information.

In summary, this is measurement devices that give you secure measurement results of the entire production without affecting the process. You do not have to take samples for laboratory testing. You do not have to worry about statistical uncertainties. In short, you get total quality control of important parameters of your product.


Sampler for vertical powder flow.