VEGA VEGAPULS 66 (≥ 2.0.0 - ≤ 3.8) standpipe ver. Profibus PA - Manual (Page 46)

Influence of the ambient temperature to the sensor electronics 11)
Average temperature coefficient of the zero
signal (temperature error) 0.03 %/10 K
Influence of the superimposed gas and pressure to the accuracy
The spreading speed of the radar impulses in gas or vapour above the product is reduced by high
pressures. This effect depends on the superimposed gas or vapour and increases with low
temperatures. The following chart shows the deviation caused by some typical gases or vapours.
The stated values refer to the distance. Positive values mean that the measured distance is too
high, negative values that the measured distance is too small.
Gas phase Temperature 1 bar/14.5 psig 10 bar/145 psig 50 bar/725 psig
Air/Nitrogen 20 °C/68 °F 0.00 % 0.22 % 1.2 %
Air/Nitrogen 200 °C/392 °F 0.00 % 0.13 % 0.74 %
Hydrogen 20 °C/68 °F -0.01 % 0.10 % 0.61 %
Hydrogen 200 °C/392 °F -0.02 % 0.05 % 0.37 %
Water (saturated
steam) 100 °C/212 °F 0.20 % - -
Water (saturated
steam) 180 °C/356 °F - 2.1 % -
Ambient conditions
Ambient, storage and transport temperature -40 … +80 °C (-40 … +176 °F)
Process conditions
For the process temperature and the vessel pressure, you also have to note the specifications on
the type label! Always the lowest value is applicable!
Process temperature (measured on the process fitting depending on process seal
-
FKM (Viton) -40 … +80 °C (-40 … +176 °F)
-
FKM (Viton) with temperature adapter -40 … +150 °C (-40 … +302 °F)
-
FFKM (Kalrez 6375) -20 … +150 °C (-4 … +302 °F)
-
graphite (coupling cone ceramic) -60 … +250 °C (-76 … +482 °F)
-
graphite (coupling cone ceramic) with
temperature adapter -60 … +400 °C (-76 … +752 °F)
Vessel pressure relating to the antenna cone
-
PTFE -100 … 4000 kPa/-1 … 40 bar (-14.5 … 580 psi)
with PN 40
-
Ceramic -100 … 16000 kPa/-1 … 160 bar (-14.5 … 2321 psi)
with PN 160
11) Relating to the nominal measuring range, in the temperature range
-40 … +80 °C .
46 VEGAPULS 66 standpipe version • Profibus PA
10 Supplement
28743
-EN
-090305