EF200F-C
Commissioning
111
10.9.4 Calculation of the measured variables
A flow computer can be found in the electronics of the measuring device with order code
for "Sensor version", option "mass (integrated temperature measurement)" and option
"mass (integrated pressure/temperature measurement)". This computer can calculate the
following secondary measured variables directly from the primary measured variables
recorded using the pressure value (entered or external) and/or temperature value
(measured or entered).
Mass flow and corrected volume flow
Medium Fluid
Standards
Explanation
Steam
1)
Water vapor
IAPWS-IF97/
ASME
• For integrated temperature measurement
• For fixed process pressure.
Gas
For fixed process pressure.
Air
NEL40
Liquids
Water
IAPWS-IF97/
ASME
‒
1)
The measuring device is capable of calculating the volume flow, and other measured variables derived
from the volume flow, across all steam types with full compensation using the pressure and temperature.
To configure device behavior → See 10.5.2
Mass flow calculation
Volume flow × operating density
• Operating density for saturated steam, water and other liquids: depends on the
temperature
• Operating density for superheated steam and all other gases: depends on the
temperature and process pressure
Corrected volume flow calculation
(Volume flow × operating density)/reference density
• Operating density for water and other liquids: depends on the temperature
• Operating density for all other gases: depends on the temperature and process pressure
