Temperature measurement during rapid solidification

An infrared pyrometer with simple construction was designed, which showed a measurement range of 923 to approximately 2273 K, a response time of less than 1 ms, a minimum target size of φ 1.4 mm and an accuracy of 1% to approximately 2%. As radiofrequency induction melting was widely applied in rapid solidification processing, a low-pass RC filter was also contrived to reduce the 300 to approximately 500 kHz high frequency disturbance by 42 to approximately 51 dB. A stepwise calibrating procedure was developed during which a pyometer was calibrated against a standard thermocouple or another well calibrated pyrometer under isothermal conditions.