Endress+Hauser Proline Prowirl F 200, Operating Instructions Manual

Page: 191 / 224

Proline Prowirl F 200 PROFIBUS PA Technical data
Hauser 191
Re
=
4 · Q [m³/s] · [kg/m³] ρ
· D [m] · µ [Pa · s]
π
i
Re
=
4 · Q [ft³/s] · [lbm/ft³] ρ
· D [ft] · µ [lbf · s/ft ]
π
i
²
A0034291
Re Reynolds number
Q Flow
D
i
Internal diameter of measuring tube (corresponds to dimension K)
µ Dynamic viscosity
ρ Density
The Reynolds number, 5 000 together with the density and viscosity of the fluid and the
nominal diameter, is used to calculate the corresponding flow rate.
Q [m /h] =
Re = 5000
³
5000 [Pa · · D [m] · · s]
i
π μ
· 3600 [s/h]
4 [kg/m ] · ³ ρ
Q [ /h] =
Re = 5000
!
³
5000 [lbf · · D [ft] · · s/ft ]
i
² π μ
· 60 [s/min]
4 [lbm/ ] ·
!
³ ρ
A0034302
Q
Re = 5000
Flow rate is dependent on the Reynolds number
D
i
Internal diameter of measuring tube (corresponds to dimension K)
µ Dynamic viscosity
ρ Density
The measuring signal must have a certain minimum signal amplitude so that the signals
can be evaluated without any errors. Using the nominal diameter, the corresponding flow
can also be derived from this amplitude. The minimum signal amplitude depends on the
setting for the sensitivity of the DSC sensor (s), the steam quality (x) and the force of the
vibrations present (a). The value mf corresponds to the lowest measurable flow velocity
without vibration (no wet steam) at a density of 1 kg/m
3
(0.0624 lbm/ft^3). The value mf
can be set in the range from 6 to 20 m/s (1.8 to 6 ft/s) (factory setting 12 m/s (3.7 ft/s))
with the Sensitivity parameter (value range 1 to 9, factory setting 5).
The value mf can be set in the range from 4.5 to 20 m/s (1.4 to 6 ft/s) for device versions
with the order code for "Calibration flow", option N "0.65% volume PremiumCal 5-point,
extended turndown". The lowest flow velocity that can be measured on account of the
signal amplitude v
AmpMin
is derived from the Sensitivity parameter and the steam quality
(x) or from the force of vibrations present (a).