عنوان مقاله [English]
Checking of flow meters and increasing their accuracy will increase the efficiency of the water distribution network, optimal use of water resources and decrease the amount of Non-Revenue water. This study was carried out to identify the amount of Non-Revenue water due to the inaccuracy of the flow meters of subscribers in the villages of Birjand. In this research, a systematic random sampling method of 1007 flow meters was used. This is equivalent to 5% of household subscribers in the villages of Birjand. Taking into account the lifetime of the flow meter, the flow meters were divided into six groups of 1-3 years, 6-4 years, 9-7 years, 10-12 years, 13-15 years and 16-18 years. The results of this study showed that 75.3% of the flow meters had an error in the allowed range and 24.7% had a higher error than the permitted range, 19.5% of them had a positive error and 5.2% had a negative error. By increasing the life of the flow meter, the precision of the flow meter is reduced and the volume of the actual flow of water is mostly recorded. According to the expenditures of 1396, the average weight of the corrected coefficient of the tested meters was 1.049 and the application of this coefficient in the consumption of the year studied subscribers and the recalculation of water bills, increased by 4.7 percent of the cost and 16.98 percent of revenue It was a company. Also, with these correction coefficients in total water consumption in 1396, the total subscribers of the province, it was found that the volume of Non Revenue water due to the lack of precision of the meter consumed 2.97% of the volume of producing water and 4.9% of the volume of allowable consumption of the company's revenue.