Very thin sensor

BETACONTROL HAS extended the applications portfolio of its IndiSpectro sensor to measure very thin and transparent films and material layers in the production process.

The new development is used for the measurement of biaxally stretched mono-films and monolayers of a thickness of five µm up to 150 µm, but also eloxal layers can be measured herewith without problems. Due to the very quick, digital signal processing, the thickness of flat material can be measured precisely. Thereby, an accuracy of +/- 0,04 µm is achieved by the contact-free and non-destructive measuring method when scanning.

This value can be improved by using the sensor statically as laboratory system that means the material is controlled without scanning the material. The method is based on the comparison of optical layer thicknesses with the wavelengths of the light. Light irradiated on a transparent layer is partially reflected at the upper as well as the lower boundary layer. By the overlay of both reflected beams, an interference spectrum arises depending on the optical refraction and the thickness of the irradiated layer.

Based on the measurement results, the final result can be determined. An additional advantage of the system is the non-appearance of the absorption effects as well as the easy handling in difficult ambient conditions. The accuracy of the IndiSpectro sensor is neither influenced by temperature nor by high humidity. But the chief attraction is the blocking out of material fluctuations caused by temperature. Due to the thermal expansion, thickness differences of the material occur during the production process. Such deviations to the final value are totally compensated by the sensor because the final thickness can be detected by the sensor at an early stage and independent of the heat. By means of a scanning rate of 40 Hz, the user receives reliable values available in milliseconds. Further the very small reject rate is a noteworthy and characteristic effect of the IndiSpectro sensor, claims the company.

Optical waveguide

The measurement system comprises an optical sensor head with an evaluation unit connected via an optical waveguide. Since it deals with a none-radiometric method, the sensor is characterized by its very convenient handling. Because of the very operation-friendly technology, neither approvals nor additional requirements for the operation are necessary.

Even the exchange of the sensor lamp is said to be easily carried out be the operator of the IndiSpectro.

Due to the separation of sensor and evaluation unit, only the sensor should be installed at the measurement place. The temperature conditions for a smooth operation are between 0 and 50° Celsius. Provided an additional cooling device is installed, a reliable measurement is possible on request at even higher temperatures. Further other ranges of wavelengths can be offered on request depending on the material and the measurement task. Betacontrol is in the position to meet customer specified requirements and to individually adopt the measurement solution.


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