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Automation Totalflow Measurement & Control Systems AGA7 Equations Design Considerations. Summary - Totalflow’s AGA-7 Implementation. Counts all pulses from primary device up 30 KHz Computes corrections for Pressure Base, Temperature Base and Compressibility
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Automation Totalflow Measurement & Control Systems AGA7 Equations Design Considerations
Summary - Totalflow’s AGA-7 Implementation • Counts all pulses from primary device up 30 KHz • Computes corrections for Pressure Base, Temperature Base and Compressibility • Adjustable Calculation Period of 1, 2, 5, 10, 30, or 60 minutes. • Compressibility (Fpv2) computed using • NX19, various method • AGA8-92 Gross Method • AGA8-92 Detail Method (up to 23 composition variables)
Summary - Totalflow’s AGA-7 Implementation • Also on a one second basis, “flow-dependent” accumulators for Pf, and Tf in order to construct averages for us in Vol Calc Period calculations. • Additional set of timed averages (independent of flow) are maintained to provide Pf and Tf averages for complete periods without flow • Adjustable flowperiod window for detecting no flow conditions (Works well for both slow speed and high speed pulse trains) • Extrapolation of live inputs during transducer calibration
Calculation Method Calculation Units Reporting Units Fpv Method Contract Hour Temperature Base Pressure Base Ft and Fp for one form of NX19 Barometric Pressure Faux - Auxiliary Factory Factor Selects Hi/Lo Limits for Pf, ACF, TF, Rate Use Fixed or Live Tf? Fixed Temperature RTD Zero Offset K Factor Use Fixed or Live Pf? Fixed Pf Pf Calibration Points (3 or 5) Fixed Composition (Events) Live Composition (No Events) Device ID (10 characters) Calculation Period Log Period Averaging Technique(Linear or Square Root) Database Size Parameters Number of Events Number of Log Period Records Number of Day Period Records AGA-7 Configuration Data Summary
Log Period is programmable (Default=60 min) Number of Log Period Records is programmable(Default = 970 records, or 40 days of hours + 10 skips) Record Size = 36 bytes Log Period Data Items Date/Time Sequence Number Raw Pulse Count Average Pf Average Tf Uncorrected Volume (ACF) Corrected Volume (MCF) Energy Flowtime Period time Discrete Alarms (24) Verification Code AGA-7 Log Period Data Summary
Number of Day Period Records is programmable (Default = 50 Day records, 40 Days + 10 Day Skips) Record Size = 100 bytes Day Period Data Items Date/Time Sequence Number Event Sequence # Starting Log Period Sequence # Ending Log Period Sequence # Contract Hour Day Period Data Items cont Uncorrected Volume (ACF) Corrected Volume (MCF) Energy Flow Time Backflow Time Period Time Discrete Alarms (24) Min, Max & Avg Pf %PF Hi, %PF Lo Min, Max & Total Pulse Count % ACF Hi, %ACF Lo Min, Max & Avg Tf %Tf Hi, %Tf Lo Verification Code AGA-7 Day Period Data Summary
AGA Calculation Error NX19 Used Methane-Gravity Alternate Analysis Used Low Lithium Battery Low Charger Pulse Measurement Error Pf Measurement Error Tf Measurement Error DO #1 Tripped DI #1 Detected Backflow Detected Zeroflow Detected ACF Below Low Limit ACF Above Hi Limit Pf Below Low Limit Pf Above Hi Limit DO #2 Tripped DI #2 Detected Tf Below Low Limit Tf Above Hi Limit AGA-7 Log Period & Day PeriodDiscrete Alarms
Number of Event Records is programmable (Default = 200 Events) Record Size = 12 bytes Event Record Data Items Date Time Event Flags (dayskip) Sequence # Event Code Old Value New Value Verification Code AGA-7 Event Log