User Manual

SP3850 Flow Computer
12
3.6 Gas Mass
Measurements:
A flowmeter measures the actual volume flow in a gas line. Temperature
and pressure sensors are installed to measure temperature and pressure.
Calculations:
• Density and mass flow are calculated using gas characteristics stored
in the flow computer.
Output Results:
• Display Results
Mass or Volume Flow Rate, Resettable Total, Non-Resettable
Total, Temperature, Pressure, Density
• Analog Output
Mass or Volume Flow Rate, Temperature, Pressure, Density
• Pulse Output
Mass or Volume Total
• Relay Outputs
Mass or Volume Flow Rate, Total, Pressure, Temperature, Density
Alarms
Applications:
Monitoring mass flow and total of gas. Flow alarms are provided via
relays and datalogging is available via analog (4-20mA) and serial outputs.
GAS MASS
Mass Flow
P . T
ref
. Z
ref
.
Mass Flow = Actual Volume Flow •
ρ
ref
•
P
ref
•
T
•
Z
ρ
ref
= Reference density
T
ref
= Reference temperature
P
ref
= Reference pressure
Z
ref
= Reference Z-factor
Calculations
Gas Mass
Illustration
Flowmeter Temperature
Transmitter
Pressure
Transmitter
STOP
START
PRINT
5
0
–
F3
CLEAR
•
MENU
ENTER
HELP
F1
4
PRE 1
3
RATE
2
TOTAL
1
GRAND
6
SCROLL
7
PRE 2
8
F2
9