VEGA VEGADIF 55 4 … 20 mA_HART - Manual (Page 22)

l R emember that due to the hydrostatic pressure of the liquid
columns in the capillaries, a zero point shift can occur. The zero
point shift can be corrected, see also "Position adjustment".
l K eep the application limits of the isolating diaphragm filling oil in
mind according to the Product Information manual VEGADIF 55,
"
Planning instructions isolating diaphragms"
Capillaries
T
o achieve more precise measuring results and avoid instrument
malfunctions, the capillaries must be mounted as follows:
Note:
l V ibration-free (to avoid additional pressure fluctuations)
l N ot close to heating or cooling lines
l I
nsulate them in cooler or warmer environment
l L ay wire with a bend radius ≥ 100 mm
l W ith isolating diaphragms on both sides, the ambient temperature
and length of both capillaries should be the same
l A lways two identical isolating diaphragms (e.g. diameter, material
etc.) should be used for the minus and plus side (standard
shipment)
+ –
+
–
≥ 100 mm
Fig. 18: Mounting VEGADIF 55 with isolating diaphragms and capillaries with
vacuum application: place the pressure transmitter below the lower isolating
diaphragm
22 VEGADIF 55 • 4 … 20 mA/HART
4 M ounting
31731
-EN
-081119