ANNEXES
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Manual EC 24 · EN05 · 2015-02
42
Permissible temperature ranges
For the standard design, the following fluid temperature and ambient temperature ranges are
permitted:
Fluid temperature range:
-20°C to +60°C
For the ambient temperature range, see the ID plate and Annex C on page 32.
Pressure loss
The pressure loss is calculated using the following formula:
4
2
M
P
DN
Q
Z
=
p
where
p
is the pressure loss
[mbar]
Z
P
is the pressure loss coefficient
is the density
[kg/m
3
]
Q
M
is the flow rate at measurement conditions
[m
3
/h]
DN is the nominal diameter of the meter
[mm]
The pressure loss coefficient ZP is:
Z
P
= 5040 (TERZ 94, TRZ 03-TE)
Z
P
= 6050 (TRZ 03-TEL)
This is an approximate mean value. The exact value is calculated from the pressure loss which is
determined on testing the volumeter.
Example of calculation:
Q
M
= 650 m
3
/h; DN 150;
= 1.3 kg/m
3
[natural gas, 600 mbar]
mbar
5
.
5
150
650
3
.
1
5040
DN
Q
Z
=
p
4
2
M
P
4
2
Therefore, the pressure loss
p with a TERZ 94 or TRZ 03-TE turbine meter is 5.5 mbar in this case.
Installation
The gas flow must be free of shocks and pulsations as well as free of foreign particles, dust and
liquids. Any components affecting the gas flow must absolutely be avoided directly upstream of the
TERZ 94 or TRZ 03-TE turbine meter.
