Endress+Hauser Flowmeter Proline 200 Brief Operating Instructions page 42

Commissioning
9. n the Reference gross calorific value parameter, enter the reference gross calorific
value of the natural gas.
10. In the Reference pressure parameter enter the reference pressure for calculating the
reference density.
 Pressure that is used as a static reference for combustion. This makes it possible to
compare combustion processes at different pressures.
11. In the Reference temperature parameter enter the temperate for calculating the
reference density.
12. In the Relative density parameter, enter the relative density of the natural gas.
Endress+Hauser recommends the use of active pressure compensation. This fully rules
out the risk of measured errors due to pressure variations and incorrect entries .
Ideal gas
The unit "corrected volume flow" is often used to measure industrial gas mixtures, in particular
natural gas. To do so, the calculated mass flow is divided by a reference density. To calculate
the mass flow, knowledge of the exact composition of the gas is essential. In practice,
however, this information is often not available (e. g. as it varies over time). In this case, it can
be useful to regard the gas as an ideal gas. This means that only the operating temperature
and operating pressure variables as well as the reference temperature and reference pressure
variables are needed to calculate the corrected volume flow. The error resulting from this
assumption (typically 1 to 5 %) is often considerably smaller than the error caused by
inaccurate composition data. This method should not be used for condensing gases (e. g.
saturated steam).
Select medium
Navigation:
Setup → Medium selection
1. Call up the Medium selection wizard.
2. In the Select medium parameter, select the Gas option.
3. In the Select gas type parameter, select the User-specific gas option.
4. For non-flammable gas:
In the Enthalpy type parameter, select the Heat option.
Configuring fluid properties
Navigation:
Setup → Advanced setup → Medium properties
5. Call up the Medium properties submenu.
6. In the Reference density parameter, enter the reference density of the fluid.
7. In the Reference pressure parameter, enter the reference pressure of the fluid.
8. In the Reference temperature parameter, enter the fluid temperature associated with
the reference density.
42
Flowmeter Proline 200
Endress+Hauser