measurement error

Optimization of Thermal Subsystem of Thermo Transducers for Measuring the Temperature of Gas Flows

The error of measuring the temperature of gas flows by contact methods consists of two main components: 1) the error that occurs in the process of measuring the physical quantity into which the temperature is converted (the error of the measuring means); 2) errors arising in the process of converting the temperature into a measured physical value using a thermo transducer.

ELECTRICAL PROPERTIES OF TI-CU-CO-SI HIGH-ENTROPY ALLOY

To study the metrological characteristics, there were studied manufactured based on the Ti-Cu-Co-Si alloy, obtained by quenching from the melt, the sensitive element of the resistance thermotransducer. The instability of its metrological characteristics as a function of temperature up to 350 oC and operation time up to 3000 hours was investigated; it does not exceed 0.025% under the worst operating conditions. In addition, the methodological error of measurement caused by heating of the sensitive element by the measuring current was examined.

Analysis of Influence of Pipeline Internal Surface Roughness on Flow Rate Measured by Means of Standard Pressure Differential Devices

The paper presents the analysis of scientific and technical sources on the influence of constructive features of pressure differential flowmeters on flow rate measurement error. According to the research results, the significant surface roughness of pipe sections downstream of the orifice plate does not significantly affect the flow measurement result. The influence of the pipe roughness upstream of the orifice plate depends on geometric characteristics of roughness, the pipe diameter, the relative area of the orifice plate throat, and the Reynolds number.

Mathematical model for temperature estimation forecasting of electrically conductive plate elements under action of pulsed electromagnetic radiation of radio-frequency range

A mathematical model for determining the temperature of an electrically conductive plate element under the action of pulsed electromagnetic radiation of the radio-frequency range is proposed.  This model allows us to take into account the influence of the process of thermoelastic energy dissipation on the forecasting of the value of temperature in addition to the joule heat.  This process is determined by thermal expansion and the action of poendromotive forces arising in the element.  This approach allows us to predict a decrease in the error of temperature determination.  On this basis, t

DEPENDENCE OF THE PYROMETRIC MEASURING TEMPERATURE ON THE EMISSIVITY FACTOR OF OBJECTS

Study  of  the  dependence  of  the  temperature  determination  error  on  the  emissivity  factor  of  materials  is conducted  in  the  paper.  The  mathematical  models,  which  describe  the  ratio  of  thermodynamic  temperature  and  measured imaginary temperatures, taking into account the emissivity factor, are analyzed. The constructions of the full radiation, brightness radiation, and spectral ratio radiation pyrometers are underpinned by the considered models.

STUDY OF THE TEMPERATURE FIELDS IN THERMOTRANSDUCER’S CASE

The choice of ways of obtaining information about the temperature of the surface layers of a moving object is the crucial in determining  the  type of  temperature transducers. This choice depends on  the  row of specific  factors:  the speed of movement of the measured object relative the object, the state of the surface, the presence of related agents in near-surface layers, the presence of disturbing factors - noise, vibration, etc. The major factor seems to be the value of the heat carried out from the diagnosed object with the help of intermediate substance.