Endress+Hauser Proline Prowirl 73 - Page 100

Description of device functions Proline Prowirl 73
100 Endress+Hauser
SPECIFIC ENTHALPY Prerequisite
The function is only available if one of the following options was selected in the SELECT
FLUID function (ä 143):
• SATURATED STEAM
•WATER
• SUPERHEATED STEAM
• USER DEFINED LIQUID with DELTA HEAT option
The function is not available if one of the following options was selected in the SELECT
FLUID function (ä 143):
• GAS VOLUME
• LIQUID VOLUME
Description
The specific enthalpy determined appears on the display.
• The enthalpy is determined using the fluid selected in the SELECT FLUID function
and the measured temperature.
• The appropriate unit is taken from the UNIT SPECIFIC ENTHALPY function
(ä 105).
• In accordance with IAPWS-IF97, the enthalpy output by the measuring device refers
to the specific enthalpy of the boiling liquid at the triple point. This means that the
specific inner enthalpy and the specific entropy of the boiling liquid are set to zero at
the triple point. It follows that the specific enthalpy is 0.611783 J/g–1 at that point.
• If the user selects USER DEFINED LIQUID with DELTA HEAT, the specific heat is
displayed here: c
p
· ÷ (q ·  (T))
Display
5-digit floating-point number
e.g. 5.1467 kJ/kg
CALCULATED
SATURATED STEAM
PRESSURE
Prerequisite
The function is only available if SATURATED STEAM was selected in the SELECT
FLUID function (ä 143).
Description
The calculated steam pressure (of the saturated steam) appears on the display.
• The steam pressure of the saturated steam is determined using the fluid selected in the
SELECT FLUID function (ä 143) and the measured temperature.
• The appropriate unit is taken from the UNIT SPECIFIC ENTHALPY function
(ä 105).
Display
5-digit floating-point number
e.g. 1.2345 kg/dm³; 1.0015 SG 20 °C
Z FACTOR Prerequisite
The function is only available if one of the following options was selected in the SELECT
FLUID function (ä 143):
• COMPRESSED AIR
•AGA NX-19
• AGA8-DC92
• ISO 12213-2
• AGA8 Gross Method 1
•SGERG-88
Description
The density determined appears on the display.
The real gas constant (Z factor) 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 calculated compressibility factor Z appears on the display if COMPRESSED AIR,
AGA8-DC92, ISO 12213-2, AGA8 Gross Method 1 or SGERG-88 is selected.
– The "supercompressibility factor" appears on the display if NATURAL GAS AGA NX-
19 is selected.
Display
5-digit floating-point number
e.g. 0.9467
Function description, MEASURING VALUES group