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6 Flow meters
Manual ERZ 2000-NG · EN07 · 2019, May 13th
247
ߩ
݃ݖ
ͳ
ʹ
ݒ
ଶ
ܿ
௩
ܶ ൌ ܿ݊ݏݐ
Where
ݒ
- Fluid speed
݃
- Gravitation constant
- Pressure
ߩ
- Density
ݖ
- Geostatic height
c
v
-
Specific heat capacity of the gas with constant volume
T
- Absolute temperature of the gas
ܿ݊ݏݐ
- Constant value
The differential pressure arising in the throat is referred to as effective pressure and
can be converted to the flow rate. A sharp edge at the inlet and a concentric ar-
rangement of the hole in the tube are important for the standard orifice plate.
Note
A significant difference to other measuring principles is that an orifice
plant and/or orifice plate measuring segment is suitable for official custo-
dy transfer calibrations, but does not have to be calibrated.
If the design conforms to ISO 5167, the material values of the gas and the pressure
differential of the flow rate can be calculated from the geometry of the throttle ele-
ments with accuracies of up to 0.2 %.
Note
Orifice plates should not be operated under 50 mm and with Reynolds
numbers under 5000 (both relative to the inside pipe diameter).
The ERZ2000-NG must be switched over to a suitable type before an orifice plate
measurement takes place (see
chapter 1.5.1 Device type adjustment
). The "orifice
plate" must be adjusted in coordinate
GB16 Volume transmitter mode
.
The special case of an revision for orifice plate measurements is presented in
ap-
pendix
Special case of revision with
orifice flow .
0
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Summary of Contents for ERZ2000-NG
Page 10: ......
Page 68: ...2 Introduction Manual ERZ 2000 NG EN07 2019 May 13th 58 Figure 44 Menu LA Overview...
Page 69: ...2 Introduction Manual ERZ 2000 NG EN07 2019 May 13th 59 Figure 45 Menu LB Totalizer BM1...
Page 77: ...2 Introduction Manual ERZ 2000 NG EN07 2019 May 13th 67 Figure 51 Overview System sub menu...
Page 241: ...6 Flow meters Manual ERZ 2000 NG EN07 2019 May 13th 231 Figure 167 Interface module C34...
Page 340: ...8 Overview Coordinates Manual ERZ 2000 NG EN07 2019 May 13th 330 8 5 6 TSV export...
Page 453: ...Certificates Manual ERZ 2000 NG EN07 2019 May 13th 443...