9th ECCC European Continuous Casting Conference – ECCC 2017

For decades most radiometric sensors have been based on photomultiplier tube technology. Berthold Technologies GmbH has lately implemented the new silicon photomultiplier technology in radiometric sensors for mould level measurement. By multiple silicon based photomultiplier chips in an array, numerous benefits have be achieved. The strong temperature dependency of the silicon photomultipliers is used to completely compensate for any aging of the scintillator and for any changes in the optical coupling. The new technology does also provide full immunity against electromagnetic influences from electromagnetic brakes or electromagnetic stirrers, and a drastically increased overall robustness. One new sensor design has e.g. been tested to endure 2 m drop tests. Also the now possible smaller form factor has enabled new ways of sensor design. One of the possibility exercised, was to design a compact sensing modules consisting of a single scintillator and a matrix of silicon photomultipliers. Such modules have then been stacked in a sensor arrangement up to eleven modules conveying simultaneously dual-phase (steel and powder) measurement capability. Other significant improvements with silicon based photomultipliers are the increased detection efficiency, the more than ten times decreased bias voltage, automatic noise detection, and the preservation of the photon energy that enables advanced spectrum analysis. The achieved improvements significantly increase product life-span, decrease life cycle cost for the end users, and enhance measurement possibility and accuracy.