Gas measurement when the core process variable is molecular weightTable 2-4:
Process variable to be reported
Process data from the
meter
Process data from ex-
ternal devices User-specified values
Molecular weight Molecular weight
Specific gravity Molecular weight Molecular weight of air
Base density Molecular weight
Base compressibility
Base pressure
Base temperature
Line density Temperature data from
meter (RTD)
(1)
Molecular weight
Line compressibility
External temperature
(2)
Line pressure
Line compressibility NX 19 Line temperature
(1)
Specific gravity
External temperature
(2)
Line pressure
% CO2
% N2
Molecular weight of air
NX 19 Mod Temperature data from
meter (RTD)
(1)
External temperature
(2)
Line pressure
% CO2
% N2
NX 19 3h Temperature data from
meter (RTD)
(1)
Specific gravity
Calorific value
External temperature
(2)
Line pressure
% CO2
% N2
Molecular weight of air
SGERG-88 Temperature data from
meter (RTD)
(1)
Calorific value
External temperature
(2)
Line pressure
% CO2
% H2
% N2
Base compressibility NX 19 Specific gravity % CO2
% N2
Molecular weight of air
Base temperature
Base pressure
NX 19 Mod Specific gravity % CO2
% N2
Base temperature
Base pressure
NX 19 3h Specific gravity
Calorific value
% CO2
% N2
Molecular weight of air
Base temperature
Base pressure
SGERG-88 Calorific value % CO2
% H2
% N2
Base temperature
Base pressure
Orientation and planning
Configuration and Use Manual 11