VEGA VEGABAR 87 Modbus and Levelmaster protocol - Operating Instructions - Manual (Page 14)

14
4 Mounting
VEGABAR 87 • Modbus and Levelmaster protocol
46297-EN-131107
2
1
Fig. 5: Temperature ranges
1 Process temperature
2 Ambient temperature
4.2 Ventilation and pressure compensation
Ventilation and pressure compensation are carried out with VE-
GABAR 87 via a filter element. It is air permeable and moisture-
blocking.
Caution:
The filter element causes a time-delayed pressure compensation.
When quickly opening/closing the housing cover, the measured value
can change for approx. 5 s by up to 15 mbar.
For effective ventilation, the filter element must always be free of
buildup.
Caution:
Do not use a high-pressure cleaner. The filter element could be dam-
aged, which would allow moisture into the housing.
The following paragraphs describe how the filter element is arranged
in the different instrument versions.
The filter element is mounted into the electronics housing. It has the
following functions:
•
Ventilation electronics housing
•
Atmospheric pressure compensation (with relative pressure meas-
uring ranges)
Filter elements
Instruments in non-Ex,
Ex-ia and Ex-d-ia version