Vega VEGAPULS 66 Operating Instructions Manual page 52

Supplement
20 mm
5 mm
-5 mm
-20 mm
Fig. 22: Accuracy VEGAPULS 66 in mm relating to the measuring range in m
0.788 in
0.197 in
- 0.197 in
- 0.788 in
Fig. 23: Accuracy VEGAPULS 66 in Inch relating to the measuring range in ft
Influence of the ambient temperature to the sensor electronics
Average temperature coefficient of the
zero signal (temperature error)
Influence of superimposed gas and pressure to the accuracy
The spreading speed of radar impulses in gas or vapour above the measured product is
reduced by high pressures. This effect depends on the superimposed gas or vapour and is
very high in case of low temperatures. The following chart shows the resulting deviation for
some typical gases or vapours. The stated values relate to the distance. Positive values
mean that the measured distance is too high, negative values that the measured distance is
too small.
Gas phase
Air/Nitrogen
Air/Nitrogen
52
0,5 m
1.640 ft
Temperature 1 bar/14.5 psi
20 °C/68 °F 0.00 %
200 °C/392 °F 0.00 %
Relating to the nominal measuring range.
11)
0.03 %/10 K
10 bar/145 psi
0.22 %
0.13 %
VEGAPULS 66 standpipe version - Profibus PA
5,85 m
19.19 ft
11)
50 bar/725 psi
1.2 %
0.74 %