VEGA VEGAPULS 62 (≥ 2.0.0 - ≤ 3.8) Foundation Fieldbus - Manual (Page 59)

Influence of the ambient temperature to the sensor electronics 7)
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
Process temperature (measured on the process fitting), depending on seal and antenna system
-
FKM (Viton) -40 … +130 °C (-40 … +266 °F)
-
FFKM (Kalrez 6375) -20 … +130 °C (-4 … +266 °F)
-
FKM (Viton) with temperature adapter -40 … +200 °C (-40 … +392 °F)
-
FFKM (Kalrez 6375) with temperature
adapter -20 … +200 °C (-4 … +392 °F)
-
FFKM (Kalrez 2035, 6230) (FDA) -15 … +130 °C (+5 … +266 °F)
-
FFKM (Kalrez 2035, 6230) (FDA) with
temperature adapter -15 … +200 °C (+5 … +392 °F)
-
FKM (Viton) with impedance cone PP -40 … +80 °C (-40 … +176 °F)
-
FFKM (Kalrez 6375) with impedance
cone PP -15 … +80 °C (+5 … +176 °F)
For the vessel pressure, you also have to note the specifications on the type label. Always the
lowest value is applicable.
7) Relating to the nominal measuring range, in the temperature range
-40 … +80 °C .
VEGAPULS 62 • Foundation Fieldbus 59
10 Supplement
28450
-
EN
-090305