CellaCombustion PK 68: Wear-free and safe temperature measurements in combustion plants

Thermocouples are traditionally used to measure temperatures in combustion plants or power plants. The problem with thermocouples is the drift of the measuring value which is a physical phenomenon and their limited life.

As the thermocouples are not necessarily directly destroyed during operation but the measurement reading slowly drifts, measurement errors are not immediately recognised.

Non-contact pyrometers that capture the infrared radiation of an object from a safe distance and calculate the temperature from the radiation values are working free of wear and free of drift. Over many years, they measure continuously and with reproducible results as long as the optical path is clean and the field of view towards the target is unobstructed. To measure temperatures, the pyrometers need an object that generates thermal radiation. In an incineration plant these objects are the hot particles in the air stream. A one-channel pyrometer determines the temperature from the average value of the radiation it captures in the measurement area. Therefore, the measurement depends on the distribution and density of the particles. With low particle density and a cooler opposite furnace wall, the reading of a one-channel pyrometer may fluctuate a lot and a too low value may be displayed.

The new compact CellaCombustion PK 68 is based on the two-colour measuring method where the radiation intensity is simultaneously detected at two wavelength ranges. The ratio of the two radiation intensities is proportional to the temperature. The advantage of this measuring method is that the measurement is not depending on the particle density. A two-colour pyrometer also reacts considerably less sensitive to the contamination of the inspection glass.

Thanks to compact enclosure with M30 thread and a high optical resolution with a narrow viewing cone, the compact device can easily be mounted on an existing furnace opening formerly used for thermocouples. Moreover, the CellaCombustion PK 68 is equipped with an electronic Smart Contamination Monitoring (SCM) function. This allows prompt reaction in case of too heavy contamination of the viewing opening, thus ensuring a high operational safety.

Even from a great distance, the measurement value can easily be read on site on the highly luminous display. All configuration parameters are adjustable on the device via keypad.