MeSys GmbH Meß- und Regelsysteme für Industrieautomation

End of beta radioisotopes in on-line web measurement

Ultra sonic non-radioactive gauge

Mesys GmbH in recent years have been growing as leader in development and production of on-line non-radioactive control systems for thickness, weight and moisture measurements.

Mesys on-line measurement systems are innovative and unique because they do not use any type of radioactive sources, because of their superior performances and easy operator's interface.

For over 50 years, beta rays have been the only system for measuring thickness or basis weight in production line of film, sheets, foil, paper and coating. Beta technology has a number of disadvantages: Systems based on betas are very sensitive to sheet movements and variations in the alignment of the heads, which, for instance, make the regulation of eventual bolts problematic and not quite precise. They measure everything between the generator and the sensor, thus also measuring the air, so that variations in air density causes errors in measurement.

Beta ray systems also have the great disadvantage of requiring special license and permission to be used. Legislations world-wide are becoming more and more restricted in giving licenses for industrial use.

Finally, their precision is not enough for some applications: the beta ray system has a maximum precision of +-0.2 g/sm +-0.5%. These precisions are fine for sheets. However, in film measurements from 2 to 20 microns, they cannot give enough precision.

Mesys GmbH has, over the past 10 years, specialized in seeking out and developing alternatives to beta method.

Today, Mesys is capable of offering all 4 fundamental non-contacting alternatives to betas:

- Ultrasound systems

- Backscatter X-ray systems

- Hovercraft sensor

- Shadow laser systems

The first technology is suitable for measuring film and coated products from just a few grams to 5.000 grams, as an alternative to Pm147, Kr85 and Strontium90 with an accuracy of 0.01 gr/sm, much higher than beta.

The X-ray Backscatter can measure from 10 microns to 5 mm with a repeatibility of 0.2% +- 0.1 gr/sm and it is used to measure non-woven product, expended products and textile.

Hovercraft sensor and Shadow laser are pure thickness sensors and have been intended for sheets from 200 microns to 30 mm.

We can thus conclude that beta systems have been finally surmounted by alternatives without radioisotopes and much more precise.