AGA XQ9801 : 2000

1 Introduction
  1.1 Scope
  1.2 Principle of Measurement
2 Terminology
3 Operating Conditions
  3.1 Gas Quality
  3.2 Pressures
  3.3 Temperatures, Gas and Ambient
  3.4 Gas Flow Considerations
  3.5 Upstream Piping and Flow Profiles
4 Meter Requirements
  4.1 Codes and Regulations
  4.2 Meter Body
      4.2.1 Maximum Operating Pressure
      4.2.2 Corrosion Resistance
      4.2.3 Meter Body Lengths and Bores
      4.2.4 Ultrasonic Transducer Ports
      4.2.5 Pressure Tap
      4.2.6 Miscellaneous
      4.2.7 Meter Body Markings
  4.3 Ultrasonic Transducers
      4.3.1 Specifications
      4.3.2 Rate of Pressure Change
      4.3.3 Exchange
      4.3.4 Transducer Tests
  4.4 Electronics
      4.4.1 General Requirements
      4.4.2 Output Signal Specifications
      4.4.3 Electrical Safety Design Requirements
  4.5 Computer Programs
      4.5.1 Firmware
      4.5.2 Configuration and Maintenance Software
      4.5.3 Inspection and Auditing Functions
      4.5.4 Alarms
      4.5.5 Diagnostic Measurements
      4.5.6 Engineering Units
  4.6 Documentation
      4.6.1 After Receipt of Order
      4.6.2 Before Shipment
5 Performance Requirements
  5.1 Definitions
  5.2 General
      5.2.1 Large Meter Accuracy
      5.2.2 Small Meter Accuracy
  5.3 Pressure, Temperature and Gas Composition
      Influence
6 Individual Meter Testing Requirements
  6.1 Leakage Tests
  6.2 Dimensional Measurements
  6.3 Zero-Flow Verification Test (Zero Test)
  6.4 Flow-Calibration Test
      6.4.1 Calibration Factors Adjustment
      6.4.2 Test Reports
  6.5 Quality Assurance
7 Installation Requirements
  7.1 Environmental Consideration
      7.1.1 Temperature
      7.1.2 Vibration
      7.1.3 Electrical Noise
  7.2 Piping Configuration
      7.2.1 Flow Direction
      7.2.2 Piping Installation
      7.2.3 Protrusions
      7.2.4 Internal Surface
      7.2.5 Thermowells
      7.2.6 Acoustic Noise Interference
      7.2.7 Flow Conditioners
      7.2.8 Orientation of Meter
      7.2.9 Filtration
  7.3 Associated Flow Computer
      7.3.1 Flow-Computer Calculations
  7.4 Maintenance
8 Field Verification Tests
9 Reference List
Appendix A: Multipath Ultrasonic Meter Flow-Calibration
            Issues
Appendix B: Electronic Design Testing - a standardized
            set of international testing specifications
            applicable to electronic gas meters
Appendix C: A.G.A Engineering Technical Note M-96-2-3,
            Ultrasonic Flow Measurement for Natural Gas
            Applications, March 1996

Discusses multipath ultrasonic transit-time flow meters, typically 6" and larger in diameter, used for the measurement of natural gas. Multipath ultrasonic meters have at least two independent pairs of measuring transducers (acoustic paths). Typical applications include measuring the flow of large volumes of gas through production facilities, transmission pipelines, storage facilities, distribution systems and large end-use customer meter sets.