Basic Principles of Improving the Accuracy of Temperature Measurement by Non-Contact Methods

Abstract

Statement of the Problem. The development of methods and means for measuring temperature and improving the accuracy of measurement, as well as the study of thermal processes of temperature distribution is a promising and urgent scientific task.
 Analysis of recent research and publications. The analysis of professional literature has shown that at present the problem of studying the temperature distribution in a particular field of activity has already been studied to some extent. However, the practical implementation of methods and means to improve the accuracy of temperature measurement is not sufficiently developed.
 The purpose of the article is to determine the fundamental factors by analyzing the theoretical and experimental material related to improving the accuracy of temperature measurement and the study of thermal processes during temperature measurements by non-contact method.
 Non-contact methods allow temperature measurement at a distance without direct contact with the object of measurement and are based on measuring the surface temperature of the object using infrared devices: pyrometers and thermal imagers. A pyrometer allows to measure the temperature of a local point of the measurement object, a thermal imager is used to visualize temperature fields. It is established that pyrometric measurement methods are based on determining the parameters of thermal radiation of the object without disturbing its temperature field. High accuracy of measurement results is achieved due to individual selection of filters and narrow spectral range.
 Conclusions. The analysis made it possible to note that the main factors that affect the accuracy of the measurement results by the pyrometer include the following: the change in the emissivity of the measurement object depending on the wavelength in the spectral range and on the temperature in the measurement range; the presence of radiation absorption in the medium between the pyrometer and the measurement object (the presence of a significant amount of dust, smoke or steam in the air in front of the sample reduces the accuracy of the measurement); geometric parameters of the field of view (visibility index) of the pyrometer Taking into account these factors in practice will increase the accuracy of the temperature measurement results by the pyrometer.

Determining features in the application of redundancy for the thermistor cubic transformation function using computer simulation

“…Also, it was established that the measurement result is not affected by a change in the parameters of the transformation function (from ±1 % to ±10 %), which negates the need to set exact parameter values for each specific type of thermistor. Thus, equation (5) can be used for any sensor with a cubic TF described by equation (3), which testifies to the universality and flexibility of RMM.…”

“…However, it should be noted that re ference scales were used in the work, which requires increased material costs. The main factors affecting the accuracy of temperature measurement by non-contact methods were considered in [3]. In [4], the impact of methods of processing results on measurement accuracy was investigated.…”