Proline Promass 84F, 84M
18
Hauser
Thermal insulation
Some fluids require suitable measures to avoid loss of heat at the sensor. A wide range of materials can be used
to provide the required thermal insulation.
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In the case of the Promass F high-temperature version, a maximum insulation thickness of 60 mm must be observed in the
area of the electronics/neck.
If the Promass F high-temperature version is installed horizontally (with transmitter head pointing upwards),
an insulation thickness of min. 10 mm is recommended to reduce convection. The maximum insulation
thickness of 60 mm must be observed.
Zero point adjustment
All Promass measuring devices are calibrated with state-of-the-art technology. The zero point determined in
this way is imprinted on the nameplate. Calibration takes place under reference operating conditions.
Consequently, the zero point adjustment is generally
not
necessary for Promass!
Experience shows that the zero point adjustment is advisable only in special cases:
• To achieve highest measuring accuracy also with very small flow rates.
• Under extreme process or operating conditions (e.g. very high process temperatures or very high viscosity
fluids).
Note the following before you perform a zero point adjustment:
• A zero point adjustment can be performed only with fluids that contain no gas or solid contents.
• Zero point adjustment is performed with the measuring tubes completely filled and at zero flow
(v = 0 m/s). This can be achieved, for example, with shut-off valves upstream and/or downstream of the
sensor or by using existing valves and gates.
– Normal operation
→
valves 1 and 2 open
– Zero point adjustment
with
pump pressure
→
Valve 1 open / valve 2 closed
– Zero point adjustment
without
pump pressure
→
Valve 1 closed / valve 2 open
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Zero point adjustment and shut-off valves
Esc
E
-
+
max.
60
max.
60
1
2
