VEGA VEGABAR 81 4 … 20 mA_HART - Operating Instructions User Manual
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4 Mounting
VEGABAR 81 • 4 … 20 mA/HART
45018-EN-131010
2
1
3
4
3
4
Fig. 6: Position of the filter element - Ex-d version
1 Single chamber housing, aluminium, stainless steel precision casting
2 Double chamber housing, aluminium, stainless steel precision casting
3 Rotatable metal ring
4 Filter element
Instruments with absolute pressure have a blind plug mounted
instead of the filter element.
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)
The process assembly of instruments with Second Line of Defense
(gastight leadthrough) is completely encapsulated. An absolute pres-
sure measuring cell is used so that no ventilation is required.
1
1
Fig. 7: Position of the filter element - gastight leadthrough
1 Filter element
With relative pressure measuring ranges, the ambient pressure is
detected and compensated by a reference sensor in the electronics.
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)
Instruments with Second
Line of Defense
Instruments in IP 69K
version