Endress+Hauser Proline Prowirl 73 - Page 151

Proline Prowirl 73 Description of device functions
Endress+Hauser 151
OPERATING-Z-FACTOR Prerequisite
The function is only available if REAL GAS was selected in the SELECT FLUID function
(ä 143).
Description
Use this function to enter the Z-factor for gas at operating conditions, i.e. for the average
temperature to be expected (for formula for calculation, see SELECT FLUID function).
The real gas constant Z indicates the extent to which a real gas differs from an ideal gas
that exactly satisfies the general gas law (p · V ÷ T = constant, Z = 1). The real gas
constant approaches the value 1 the further the real gas is from its liquefaction point.
The Z-factor can be determined using the "Applicator" software (ä 62).
User input
5-digit floating-point number
Factory setting
1.000
REFERENCE PRESSURE Prerequisite
The function is only available if the following was selected in the SELECT FLUID
function (ä 143):
• COMPRESSED AIR
• CARBON DIOXIDE
• NITROGEN
•OXYGEN
• GAS MIXTURE
•ARGON
•METHANE
• NATURAL GAS
•REAL GAS
Description
Use this function to enter the reference pressure of the fluid to calculate the reference
density. This is needed to calculate the corrected volume flow (ä 98).
The appropriate unit is taken from the UNIT PRESSURE function (ä 106).
User input
5-digit floating point number (value entered must be > 0)
Factory setting
1.013 bara
REFERENCE
TEMPERATURE
Prerequisite
The function is only available if one of the following was selected in the SELECT FLUID
function (ä 143):
• COMPRESSED AIR
• CARBON DIOXIDE
• NITROGEN
•OXYGEN
• GAS MIXTURE
•ARGON
•METHANE
• NATURAL GAS
•REAL GAS
Description
Use this function to enter the reference temperature of the fluid to calculate the reference
density. This is needed to calculate the corrected volume flow (ä 98).
The appropriate unit is taken from the UNIT TEMPERATURE function (ä 102).
!
Note!
This setting does not change the permitted temperature range of the measuring system.
Pay attention to the temperature application limits specified in the product specifications
(ä 84).
User input
5-digit floating-point number
Factory setting
273.15 K
Function description, FLOW COMPUTER group