This regulation is applicable to initial verification, subsequent verification and in-use inspection of diaphragm gas meters (hereinafter referred as gas meters).
2 Normative References
The following documents are referenced in this regulation:
JJF 1001-2011 General Terms in Metrology and Their Definitions
GB/T 6968-2011 Diaphragm Gas Meters
OIML Rl37-1&2: 2012 Gas Meters
0IML D11:2004 General Requirements for Electronic Measuring Instrument
EN 1359:1998+A1:2006 Diaphragm Gas Meters
For dated references, only the edition cited applies. For undated references, the latest edition of the normative document (including any amendments) applies.
3 Terms and Measuring Units
3.1 Terms
3.1.1 Maximum flow-rate qmax
The upper limit of flow-rate of gas meter complying with metering performance.
3.1.2 Minimum flow-rate qmin
The lower limit of flow-rate of gas meter complying with metering performance.
3.1.3 Transitional flow-rate qt
The flow-rate between the maximum and minimum flow-rate, dividing the flow-rate range of gas meter into "high area" and "low area". Both high area and low area are subject to corresponding maximum permissible error. qt equals to 0.1qmax.
3.1.4 Flow-rate range
The range limited by the maximum and minimum flow-rate complying with the metering performance of gas meter.
3.1.5 Maximum operating pressure pmax
The upper limit of gas meter operating pressure.
3.1.6 Pressure loss △p
The average pressure drop between air inlet and air outlet under maximum flow-rate.
3.1.7 Integrating value Q
Introduction I 1 Scope 2 Normative References 3 Terms and Measuring Units 3.1 Terms 3.2 Measuring Units 4 General 4.1 Principle and Structure 4.2 Purpose 5 Measuring Performance Requirements 6 General Technical Requirements 6.1 Nameplate and Marking 6.2 Appearance 6.3 Flow-rate Range 6.4 Indicating Device 6.5 Sealing 6.6 Pressure Loss 6.7 Ancillary Devices 6.8 Safety Performance 7 Control of Measuring Tools 7.1 Verification Conditions 7.2 Verification Items 7.3 Verification Methods 7.4 Verification Result Treatment 7.5 Verification Cycle Appendix A Function Test for Ancillary Devices of Gas Meters Appendix B Information and Format for Inside Page of Verification Certificate/Verification Result Notice
