Vega VEGAFLEX 81 - Page 16

16
4 Mounting
VEGAFLEX 81 • Modbus and Levelmaster protocol
42283-EN-140430
The reference plane for the measuring range of the sensors is the
sealingsurfaceofthethreadorange.
Keep in mind that a min. distance must be maintained below the refer-
ence plane and possibly also at the end of the probe - measurement
in these areas is not possible (dead band). These dead bands are
listed in chapter "Technicaldata". Keep in mind for the adjustment that
the default setting for the measuring range refers to water.
Theprocessttingmustbesealedifthereisgaugeorlowpressurein
the vessel. Before use, check if the seal material is resistant against
the measured product and the process temperature.
Themax.permissiblepressureisspeciedinchapter"Technical
data" or on the type label of the sensor.
Vapours, superimposed gases, high pressures and temperature dif-
ferences can change the spreading speed of radar impulses.
There are two possibilities to correct these deviations.
Corrective value in the process control system
Inthetechnicaldataunder"Inuenceofsuperimposedgasandpres-
sureonaccuracy"youcanndatablewithdeviationvaluesinsome
typical gases or in steam.
In the control system (DCS) you can correct the measurement results
of the VEGAFLEX 81 with these values.
The prerequisite is constant temperature and pressure in the vessel.
Automatic correction via the reference distance
The VEGAFLEX 81 can be equipped optionally with a running time
correction via reference distance. The probe can carry out an auto-
matic running time correction with it.
Thereferencepointmusthencenotbeoverlled.Theupperdead
band is hence 450 mm (17.7 in).
Measuring range
Pressure
Steam boiler applications