Universal Flow Computer UR06
Operating Manual
Page 40 of 55
Subject to changes
A-EN-08728-URRev.B
Bopp & Reuther
Messtechnik GmbH
mineral oil 15°C). The calculation is carried out for all the media.
The base pressure and base temperature are used to internally calculate the base density.
Range:
0°C
... 100.0°C
17.10.5 Isentropic exponent
If the primary or secondary transmitter is an orifice, the isentropic exponent is entered here. Refer to
the literature for the values of various media.
Range:
1.1 ... 3
17.10.6 Compressibility
A fixed correction value can be entered here for media (fluids) for which the stored density calculations
do not consider the compressibility.
The pressure dependence of the density is considered internally for water, steam and air.
The compressibility for hydro carbonates is calculated according to MPMS 11.2.1M or 11.2.2M (the
selection is made automatically according to the density at 15 °C) or can be specified as a constant.
Range:
0.5 ... 2
17.10.7 Saturated pressure monitor
The saturation status can be monitored for steam, NGL and LPG measurements.
Steam:
If activated and the pressure exceeds the vapor pressure a vapor pressure fault is
reported.
LPG / NLG: If activated and the pressure falls below the vapor pressure a vapor pressure and volume
fault is reported.
Selection:
No
, Yes
17.10.8 Pressure reserve
The switching point of the vapor pressure monitor can be controlled via the pressure reserve.
Steam:
switching point = pressure > (vapor pressure – pressure reserve)
LPG / NLG: switching point = pressure < (vapor pr pressure reserve)
Range:
0.0 … 10.0 bar
17.10.9 Dynamische Viskosität 0°C
Die dynamische Viskosität wird bei Gasen nach der Gleichung von Sutherland berechnet.
Bereich:
1E-6 ... 1E-3 Pa s
17.10.10 Sutherland-Konstante
Die dynamische Viskosität wird bei Gasen nach der Gleichung von Sutherland berechnet.
Bereich:
-100 ... 1000
17.11
Redlich Kwong
17.11.1 Critical pressure
The compressibility for gas can be calculated according to Redlich Kwong. The critical pressure is a
parameter and is entered here. Refer to the literature for the values of various media.
Range:
1.0 bar ... 2,000.0 bar
17.11.2 Critical temperature
The compressibility for gas can be calculated according to Redlich Kwong. The critical temperature is
a parameter and is entered here. Refer to the literature for the values of various media.
Range:
1 K ... 2,000 K
17.12
Density
17.12.1 Density determination
Control of density determination. If set to default calculation is done with a constant density. With P-T
(default), the fluid as well as the pressure and temperature are used to calculate the density. The
density can also be handled as a measured value via current or frequency.
