The CellaCrystal PA 44 has been developed for optical temperature measurement in the cultivation of crystals. The calibration is specially adapted to the production of crystals. Combined with the constant high resolution of < 0.1 K over the entire measuring range and the very high long-term stability, the device meets the requirements for the necessary high measuring accuracy. With the help of the through-the-lens sighting, laser pilot light or video camera, the pyrometer can be precisely aligned to the measuring point.