OVREDNOTENJE VISOKOTEMPERATURNE KALIBRACIJSKE PEČI

RUTAR, MIHA (author), Pušnik, Igor (mentor)

Kalibracijska peč je namenjena kalibriranju termočlenov in uporovnih termometrov. Kalibracije le-teh so pomembne za čim bolj točno merjenje temperature. Zato je pred uporabo potrebno ovrednotiti oz. kalibrirati samo kalibracijsko peč. Le tako se lahko prepričamo o njeni točnosti in s tem verodostojnosti kasnejših kalibracij, ki jih z njo opravljamo. V diplomskem delu sem ovrednotil kalibracijsko peč FLUKE 9118A iz Laboratorija za metrologijo in kakovost. Določil sem njeno temperaturno stabilnost in homogenost. Meritve sem opravljal z vstavljenim keramičnim stabilizacijskim blokom ter brez njega. Te meritve so ključnega pomena za kasnejše določanje negotovosti kalibracij termometrov. S keramičnim stabilizacijskim blokom sem izvajal meritve pri temperaturah 300 °C, 500 °C, 800 °C, 1000 °C in 1200 °C, brez bloka pa pri 500 °C, 750 °C, 1000 °C in 1200 °C. Merilni termometer sem iz začetne točke pri popolni potopitvi pomikal ven po korakih (3 cm). Referenčni termometer je pri vseh meritvah ostal na istem mestu – to je pri popolni potopitvi.  Pri uporabi stabilizacijskega bloka sem izvajal meritve do odmika 15 cm od popolne potopitve ali do tam, kjer je razlika temperature presegla 0,5 °C.  Meritve brez stabilizacijskega bloka sem izvajal do odmika 9 cm. Pri temperaturah 300 °C in 500 °C z izolacijskim blokom sem uporabljal kalibriran uporovni termometer, pri višjih temperaturah in pri meritvah brez stabilizacijskega bloka pa kalibrirane termočlene tipa S.

• Language: Slovenian
• Keywords: kalibracijska peč, termočlen, uporovni termometer, ovrednotenje, temperaturna stabilnost, temperaturna homogenost
• Work type: Bachelor thesis/paper
• Organization: FE - Faculty of Electrical Engineering
• Year: 2016
• PID: 20.500.12556/RUL-81016
• Publication date in RUL: 23.03.2016

Secondary language

• Language: English
• Title: EVALUATION OF A HIGH TEMPERATURE CALIBRATION FURNACE

Abstract

Calibration furnace is designed for calibrating thermocouples and resistance thermometers. Calibrations of those are important for most accurate temperature measurement. That is why the furnace needs to be evaluated and calibrated before use. This is the only way to be sure about it's accuracy and credibility of later calibrations. In my thesis I evaluated calibration furnace FLUKE 9118A from the Laboratory of metrology and quality. I determined its themperature stability and homogenity. I was performing the measurements with the inserted ceramic isothermal block and without it. These measurements are essential for determining calibration uncertainties of thermometers later on. I was performing measurements with the ceramic isothermal block at temperatures of 300 °C, 500 °C, 800 °C, 1000 °C and 1200 °C, and without isothermal block at 500 °C, 750 °C, 1000 °C and 1200 °C. I was pulling a measurement thermometer from the starting point of full immersion out by steps of 3 cm. The reference thermometer was fully immersed at all times.  While using isothermal block I was performing measurements until I reached a 15 cm offset from full immersion or to the point where the temperature difference was greater than 0,5 °C.  I performed measurements without isothermal block until reaching 9 cm offset from full immersion. At temperatures of 300 °C and 500 °C using isothermal block I used the calibrated resistance thermometer and at higher temperatures and measurements without isothermal block I used the calibrated type S thermocouples.

• Keywords: calibration furnace, thermocouple, resistance thermometer, evaluation, temperature stability, temperature homogeneity