MEASUREMENT UNCERTAINTY OF A TEST RIG FOR WATER METERS

摘要

The accuracy of test rigs for water and flow sensors of heat meters depends on several parameters of the device and the performance of the calibration. Therefore the expanded uncertainty of a new test rig of the BEV, the Austrian Metrological Service, was determined by investigating the relevant influences. This measuring device allows to control the flow rate in a very wide range from 6 l/h up to 170.000 l/h as well as the temperature from 8℃ up to 90℃, in the pressurized case up to 130℃, and the pressure up to 6 bar. At first a theoretical analysis of uncertainty was performed in line with the ,,Guide to the expression of Uncertainty in Measurement" (ISO Guide) followed by experimental tests. The following contribution presents the basic ideas and the results of the investigations.