Views: 1 Author: Site Editor Publish Time: 2022-02-22 Origin: Site
Accurate grades of residential water meters are divided into several grades
The accuracy of the water meter is divided into: A, B, C, D
The D-level is the highest, and the B-level is basically used in China.
The water meter standard of 1996 was marked on the movement of the water meter.
GB/T778-2007 The new water meter standard Some water meter cores do not mark how many grades, but there are flow parameters to represent the grade of the water meter.
Water meters are instruments for measuring water flow. Most of them are cumulative flow measurements of water. They are generally divided into two categories: volumetric water meters and speed water meters. They originated in the United Kingdom. The development of water meters has a history of nearly two hundred years. , you should first estimate the size and flow range of the flow rate used under normal circumstances, and then select the water meter of the specification with the common flow rate closest to this value as the first choice.
Minimum flow (Q1): The minimum flow that requires the indication of the water meter to meet the maximum allowable error.
Boundary flow rate (Q2): The flow rate that occurs between the normal flow rate Q3 and the minimum flow rate Q1, dividing the flow rate range into two zones, "high zone" and "low zone", each with a specific maximum allowable error.
Usual flow (Q3): The maximum flow under rated operating conditions. At this flow rate, the water meter should work properly and meet the maximum allowable error requirements.
Overload flow (Q4): The water meter is required to meet the maximum allowable error requirements in a short period of time, and then the maximum flow rate that can still maintain the metering characteristics under rated operating conditions.
Pressure loss (Δp): At a given flow rate, the head loss caused by the presence of a water meter in the pipeline.