Investigation of thermal radiation and temperature measurement by optical pyrometer
Fizikos laboratorinis darbas. Investigation of thermal radiation and temperature measurement by optical pyrometer. Method and basic formulas.
Objevtives: By using optical Pyrometer deduce temperature of heated object and deduce Stefan-Boltzmann constant.
Equipment: Pyrometer, heating lamp, voltmeter, ampermeter, power source.
Method and basic formulas: When bodies are heated to particular temperature they start to glow electromagnetic waves. Such emission of waves is called thermal. Thermal glowing can be described by its energy flow. The energy flow can be expressed by its emittance:
Experimental emittance correlation with frequency of different temnperatures T1 and T2 can be shown as:
All bodies more or less absorbs electromagnetic waves.