High-speed spectral pyrometer based on a «Kolibri-2» spectrometer

Abstract

The operation speed of commercially available spectral-ratio pyrometers and brightness pyrometers often appears insufficient for control of fast-changing temperature (e.g., in a graphite cell of an AES electrothermal atomizer, the rate temperature change is 104°C/sec). An advantage of spectral pyrometers is high speed and ability to measure the temperature of objects with unknown emissivity. The goal of this study is to develop a high-speed spectral pyrometer based on a «Kolibri-2» spectrometer with BLPP-2000 photodetector array that provides a wide working wavelength range 400 – 1050 nm, and minimum basic exposure time of 0.4 msec. The temperature was calculated by plotting the emission spectrum of the object in Wien coordinates (with allowance for calibration of the spectral pyrometer using radiation source of the known temperature) and measuring slope of the obtained graph. The relative error of temperature measurements on a spectral pyrometer estimated by comparing measurement results and data obtained with a calibrated Termokont-TN5S1M (Termokont company) single-channel pyrometer was not more than 1.5% in a temperature range of 1000 — 2400°C and higher, and rapidity up to 2500 measurements/sec. The results of measuring temperature of the graphite cell of the electrothermal atomizer using a spectral pyrometer during sample atomization at a rate of temperature change up to 10 000°C/sec are presented.