Manual

13
SP4000 Flow Computer
3.1 Corrected Gas Volume
Measurements:
A flowmeter measures the actual volume flow in a gas line. Temperature and pressure
sensors are installed to correct for gas expansion effects.
Calculations:
• Corrected Volume is calculated using the flow, temperature and pressure inputs as
well as the gas characteristics stored in the flow computer (see "FLUID DATA"
submenu). Use the "OTHER INPUT" submenu to define 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 flow 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
PT
ref
Z
ref
Corrected Volume Flow = Volume Flow •• •
P
ref
TZ
Calculations
Corrected
Gas Volume
Illustration
Flowmeter Temperature
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
3. Applications