KEP ES749 - 3.5 Corrected Gas Volume

ES749 Flow Computer
15
3.5 Corrected Gas Volume
Measurements:
A owmeter measures the actual volume ow in a gas line. Temperature and pressure
sensors are installed to correct for gas expansion effects.
Calculations:
• Corrected Volume is calculated using the ow, temperature and pressure inputs as well
as the gas characteristics stored in the ow computer (see "FLUID DATA" submenu).
Use the "OTHER INPUT" submenu to dene reference temperature and reference
pressure values for standard conditions.
Output Results:
• Display Results
Corrected Volume or Actual Volume Flow Rate, Resettable Total, Non-Resettable
Total, Temperature, Pressure, Density (optional: peak demand, demand last hour,
time/date stamp)
• Analog Output
Corrected Volume or Actual Volume Flow Rate, Temperature, Pressure, Density,
Peak Demand, Demand Last Hour
• Pulse Output
Corrected Volume or Actual Volume Total
• Relay Outputs
Corrected Volume or Actual Volume Flow Rate, Total, pressure, Temperature
Alarms, Peak Demand, Demand Last Hour
Applications:
Monitoring corrected volume ow and total of any gas. Flow alarms are provided via relays
and datalogging is available via analog (4-20mA) and serial outputs.
CORRECTED
GAS VOLUME
Volume Flow
Pulse Input; Average K-Factor
input frequency • time scale factor
Volume Flow =
K-Factor
Analog Input; Linear
Volume Flow = % input • Full Scale Flow
Corrected Volume Flow
P T
ref
Z
ref
Corrected Volume Flow = Volume Flow • • •
P
ref
T Z
Calculations
Corrected
Gas Volume
Illustration
FlowmeterTemperature
Transmitter
PRINT
5
0
–
TIME
CLEAR
•
MENU
ENTER
HELP
TEMP
4
PRE 1
3
RATE
2
TOTAL
1
GRAND
6
SCROLL
7
PRE 2
8
DENS
9
Pressure
Transmitter