VEGA VEGADIF 55 4 … 20 mA_HART - Manual (Page 21)

à Mount VEGADIF 55 below the measurement loop so that the
effective pressure lines are always filled with liquid and gas
bubbles can bubble up to the process line
à For measurements in products with solid content such as e.g. dirty
liquids, the installation of separators and drain valves is
recommended to enable collection and removal of debris and
sediment.
+ –
1
4
2 2
3
Fig. 17: Measurement setup, differential pressure measurement in gases,
vapours and liquids with VEGADIF 55
1
Cell isolating diaphragm
2 Capillaries
3 E.g. filter
4 VEGADIF 55
à Mount isolating diaphragm with capillaries on top or laterally on the
pipeline
à In vacuum applications: Mount VEGADIF 55 below the measure-
ment loop
à The ambient temperature should be the same for both capillaries
4 .5 Mounting for instruments with isolating
diaphragms
Isolating diaphragm
N
ote these general instructions to the isolating diaphragms:
Note:
l A n isolating diaphragm together with a pressure transmitter forms
a closed, calibrated system which is filled through openings in the
isolating diaphragm and the measuring element of the pressure
transmitter. These openings are sealed and must not be opened!
l D o not clean or touch the isolating diaphragm with hard or sharp
subjects
l R emove the diaphragm protection just before installation
l W hen using a mounting strap, there must be sufficient strain relief
for the capillaries to avoid bending them (bending radius ≥ 100 mm)
Differential pressure
measurement in gases,
vapours and liquids
VEGADIF 55 • 4 … 20 mA/HART 21
4 M ounting
31731
-EN
-081119