What Are the Requirements for Regular Verification of Smart Water Meters?
The number of smart water meter users is increasing year by year, and the cost of water is also increasing. How to ensure the accuracy of water meter measurement and improve work efficiency is particularly important. The water meter has undergone strict quality inspection. However, the daily use and use environment will also cause great wear and tear to the water meter. To ensure that the water meter can still accurately measure water consumption after one or two years, it is necessary to conduct regular verification of the smart water meter.
The water meter verification must be strictly implemented in accordance with the requirements of the current effective verification rules of the national JJG162-2009 cold water meter. The verification of the indication error of the water meter must meet the relevant technical conditions and verification conditions:
1. Standard water meter verification device
The water meter verification device must be evaluated by the standards of the government's measurement administrative department and have a valid measurement standard certificate. The accuracy shall not exceed one-fifth of the maximum allowable error of the water meter. When using a water meter for calibration, the uncertainty of the calibration device should not be greater than one third of the maximum allowable error of the water meter.
2. Installation requirements of the tested water meter
During validation, changes in diameter of elbows, pumps, spinal tubes and upstream tubes should be avoided. It is also stipulated that the upstream straight pipe section of the water meter to be tested shall not be less than DN10, and the downstream straight pipe section shall not be less than DN10. Not less than DN5 or install an equivalent straightener. The verification medium should be pure water and the water should not contain air bubbles.
3. Necessary requirements for water meter verification
①Verify water pressure: the inlet water pressure of the water meter should be less than or equal to the maximum working pressure of the water meter to be tested, and the outlet water pressure should be greater than or equal to 0.03MPa.
②The water temperature for verification is 20℃±10℃, and the change of water temperature during the verification process shall not exceed 5℃.
③ During the verification process, the water flow should be constant at the selected value, and its relative change during the verification process: low area ≤±2.5%, high area ≤±5%.
④ The verification water consumption is not less than 200 times the minimum verification division value of the water meter to be tested, and generally no less than the volume corresponding to the verification flow for 1 minute. Commonly used verification water consumption is 100L, 20L and 10L respectively.
