Pyrometer

Розглянуто вплив шумів приймача випромінення на похибку пірометра у процесі його калібрування. Визначено математичну залежність між похибкою вимірювання температури та відношенням сигнал/шум за різної кількості спектральних каналів пірометра, що досліджено за допомогою математичного моделювання.

Eradiation receiver impact on the pyrometer error in the process of calibration has been considered in the proposed article. The mathematical dependence of temperature measurement error on signal/noise ratio at various amount of spectral pyrometer channels is determined by the modeling.

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.

The major error of temperature measurements of different objects is due to uncertainty of their emissivity factor value. And vice versa, for correct determination of a true temperature, using conventional temperature means (pyrometers, thermal image cameras), one has to know in advance the emissivity factor of the studied object’s surface or better to set its value in place immediately  before  a  measurement.  The  latter  is  proposed  by  authors  to  significantly  increase  the  accuracy  of  temperature measurement.

Two main methods of contact measurement of steel temperature are applied in industry: with help of disposable  and multiple  used  thermotransducers.  Reusable  ones  are  fixed  to  the  bottom  of  the  graphite  tip  fixed directly on the reinforcement. Then they are able to measure the temperature of the graphite surface. Since it needs to even the graphite temperature and the temperature of the melt metal, the measuring takes some extra time. Therefore the  thermotransducer  is mounted  in  the metal  for a  long  time.