NIR-II

M.Sc.

Florian Treiber

Forschung & Entwicklung

The NIR-II sensor represents the logical evolution of the NIR sensor, which originally emerged from a joint research project with GTV Verschleißschutz GmbH. The underlying measurement technology enables precise monitoring and targeted optimisation of process parameters in thermal HVOF and plasma spraying processes.

The sensor detects individual particles in the spray jet in real time and analyses them to precisely determine key process parameters such as velocity and surface temperature.

The continuous monitoring of these key parameters ensures reproducible process control, supports quality management and contributes significantly to the stabilisation and increased efficiency of the plasma spraying process.

Industrial applicationsIndustrial applications

The NIR-II sensor is positioned inside the spray booth at a specific distance from the spray jet. The sensor is secured using a guide rail with a clamping lever, ensuring flexible and secure installation.

Thanks to the plug-and-play mounting principle, the sensor can be installed and commissioned quickly. All components required for commissioning are included in the scope of delivery.

Our accompanying software is intuitively designed and self-explanatory, enabling simple and efficient operation.

Measuring principleMeasuring principle

The particle beam is illuminated by a pulsed NIR laser. The laser light reflected by the passing particles, as well as their intrinsic thermal emission, is distributed across three detectors via two beam splitters and evaluated separately.

The reflection signal is used for the precise detection of individual particles. A specially developed algorithm determines the exact moment the particles pass through the measurement spot and calculates the particle velocity from this. At the same time, the thermal emission is split into two spectral ranges. The surface temperature of the particle is determined from the intensity ratio of these two signals using the principle of two-colour pyrometry.

In this way, up to 300 particles per millisecond can be analysed in real time. Velocities in the range of 100 m/s to 1500 m/s and surface temperatures between 800 °C and 3500 °C are reliably recorded.