STATISTICAL MODELLING OF ERROR MEASUREMENT FOR DIAPHRAGM GAS METERS AT DIFFERENT AMBIENT TEMPERATURES

In this research, a statistical modeling is introduced in order to evaluate measuring error of diaphragm gas meters considering the effects of different ambient temperatures on the usual (0.2Qmax) and maximum (Qmax) consumption flow rate. In this study, a G4 diaphragm gas meter was used because of its prevalence in Iran. By considering the climate of Iran, average range of experiment's temperature was chosen between 30°C to 60°C and 0°C to -30°C. For conducting the experiments on these gas meters, a heater-cooler device and a master chamber were utilized. Proposed statistical modeling was able to evaluate the amount of using gas in the form of 0.2Qmax and Qmax. The obtained results may be used as a correction factor for diaphragm meter operation on different temperature conditions. In other words, the advantages of this research can be used for estimating the proper amount of using gas and calculating the proper fee for the user. According to results, in the countries that the gas consumption is done by diaphragm gas meters, national gas company will be lost for cold cities and will be profited for warm cities and the amount of fee estimation error is significant. As an example, national gas company of Iran lost about 40.7 million dollars for gas consumption measurement error for Tehran city in 2008. [PUBLICATION ABSTRACT]