1. Automation Totalflow Measurement & Control Systems AGA7 Equations
Design Considerations

2. 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)

3. 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

4. AGA-7 Configuration Data Summary
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

5. AGA-7 Log Period 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

6. AGA-7 Day 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

7. AGA-7 Log Period & Day Period Discrete Alarms
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

8. AGA-7 Event Log
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