Characterization of High Temperature Calibration Bath through Stability and Uniformity Tests with Data Acquisition using Standard Platinum Resistance Thermometer and Precision Multimeter

Calibration is one area in measurement where our country is still in the process of improvement. The absence of confirmed approaches and actions for identifying the features of calibration baths by numerous laboratories disallowed them to assess more the finest measurement ability and develop their accurateness. In recent advances in technology, there is now a way of providing the best measurement capability in temperature calibration by providing validated methods in characterizing calibration baths that contributes to the uncertainty of measurement of the calibrated thermometer and is therefore important to measure the extent of its contribution to the final uncertainty. This study adapted the process from obtainable and current methods. Platinum Resistance Thermometer (PRT-Isotech) and Standard Platinum Resistance Thermometer (SPRT-Hart) which are interfaced to Precision Digital Multimeters were used for measurements. Quite a few measurements were made at varying time durations implemented on several known positions in an orderly measurement form which enclosed the whole workspace. The uniformities and stabilities of the calibration bath were computed by getting the range of the Minimum Difference with the Maximum Difference taken at every established temperature point. Outcomes of measurements exhibited that the calibration bath stability at every temperature setting are steadier at lesser temperatures and have a tendency to rise as the temperature approaches 250ºC. The liquid bath was further unvarying at lesser temperatures. The variances found were insignificantly distributed since the Standard Deviation ranged only from 0.005 to 0.013. It indicates that the local calibration laboratories can also perform the tests for stability and uniformity on a calibration bath at an accuracy level comparable to national laboratories since the measured values obtained were within the values obtained in similar tests conducted in a national laboratory abroad and have very small standard deviations.