Evaluation and Expression of Uncertainty in the Calibration of Screw Type Industrial Lamps using Photoelectric Pyrometer

摘要

The paper describes the details of estimation and expression of uncertainty by universal method in the temperature measurement and calibration of special type of industrial ribbon lamp (screw type) by comparing it against spectral photoelectric linear pyrometer in the high temperature range above 1000 deg C using high stability transfer standard tungsten lamps. It is an indirect calibration where the photocurrent generated by the radiating lamp provides a means to compare the temperature. The intensity of radiation depends upon the current flowing through the lamp, which is precisely measured. Thus the lamp is calibrated in terms of temperature versus the current flowing through it. A sufficient number of data were taken on the measurement of photocurrent of radiating lamps to calculate the uncertainty in the temperature with a confidence-level of 95percent approximately for a normal probability distribution. The calculation of uncertainty was supported by a case study on calibrating industrial lamps, one at 1000 deg C and the other at 2200 deg C. The results of calibration are reported to be 1000 deg C +- 2.54 deg C for lamp No.192A (lamp current 4.9916 A) and 2200 deg C +- 3.64 deg C for lamp No.952B (lamp current 17.8459 A) respectively.