A High-Speed Spectral Pyrometer Based on a Kolibri-2 Spectrometer

Abstract

The operating speed of commercially available spectral-ratio pyrometers and brightness pyrometers often appears insufficient for control of a fast-changing temperature (e.g., in a graphite cell of an AAS electrothermal atomizer, whose temperature increases at a rate of 10⁴ °C/s). An advantage of spectral pyrometers is high speed and ability to measure the temperature of objects with unknown emissivity. The goal of this work is to develop a high-speed spectral pyrometer based on a Kolibri-2 spectrometer with a BLPP-2000 photodetector array that provides a working wavelength range of 400–1050 nm and a minimum basic exposure time of 0.4 ms. The temperature was calculated by plotting the emission spectrum of the object in Wien coordinates (with allowance for calibration of the spectral pyrometer using a radiation source of known temperature) and by measuring the slope angle of the obtained graph. The relative error of temperature measurements with a spectral pyrometer estimated by comparing the measurement results and the data obtained with a calibrated Termokont-TN5S1M single-channel pyrometer (Termokont company) was no more than 1.5% in a temperature range of 1000–2400°C and higher and the operating speed was up to 2500 measurements/s. The results of measuring the temperature of the graphite cell in the electrothermal atomizer using a spectral pyrometer during sample atomization at a rate of the temperature increase up to 10 000°C/s are presented.