DETERMINAREA NUM?RULUI OPTIM DE CICLURI DEM?SURARE LA ETALONAREA CALIBRATOARELE DE PRESIUNE

摘要

This work presents the calculation of the optimal number of measurement cycles used in calibration ofrnthe pressure calibrators. As we know the pressure calibrators are smart transducers [5] having highrnmetrological performances. They are very accurate and more stable than transducers and are used asrnstandards in calibration of the transducers. The specialists from INM have elaborated a calibrationrnmethod, a procedure of calibration [3] and working instructions [4] for pressure calibrators.rnEvaluation of the uncertainty [2] in calibration of the pressure calibrators is very important and needrna good experience. In conformity with [3] the uncertainty of measurement, associate with the result ofrnmeasurement, have to be maximum ? from the tolerate error of the pressure calibrator. In therncalibration of the apparatus with elastic sensing element, the repeatability of the measurements is veryrnimportant and this can be smaller if the number of measurement cycles is bigger. Because the value ofrnrepeatability is multiplied with the Student coefficient we need more number of measurement cycles,rnbut this takes more time and more money. This work describes the calculation of the measurementrnuncertainties, in calibration of the pressure calibrators, for 2, 3 and 6 cycles of measurements. As werncan see in figure 1 , the optimal number of the measurement cycles, take into account the Studentrncoefficient and the condition for the value of uncertainty, is three.