Vega VEGAPULS 62 Operating Instructions Manual page 80

11 Supplement
10 mm (0.394 in)
2 mm (0.079 in)
0
- 2 mm (- 0.079 in)
- 10 mm (- 0.394 in)
Fig. 57: Deviation under reference conditions
1 Reference plane
2 Antenna edge
3 Recommended measuring range
Variables influencing measurement accuracy
Temperature drift - Digital output
Additional deviation through electromag-
netic interference acc. to EN 61326
Influence of the superimposed gas and pressure on measurement accuracy
The propagation speed of the radar impulses in gas or vapour above the medium is reduced by
high pressure. This effect depends on the type of superimposed gas or vapour and is especially
large at low temperatures.
The following table shows the resulting deviation for some typical gases and vapours. The specified
values refer to the distance. Positive values mean that the measured distance is too large, negative
values that the measured distance is too small.
Gas phase Temperature
Air 20 °C/68 °F
200 °C/392 °F -0.01 %
400 °C/752 °F -0.02 %
Hydrogen 20 °C/68 °F
200 °C/392 °F -0.02 %
400 °C/752 °F -0.02 %
Steam (satu- 100 °C/212 °F 0.26 %
rated steam)
180 °C/356 °F 0.17 %
264 °C/507 °F 0.12 %
366 °C/691 °F 0.07 %
Characteristics and performance data
Measuring frequency
80
0,5 m (1.6 ft)
1 2
1 bar
(14.5 psig)
0 %
-0.01 %
< 3 mm/10 K, max. 10 mm
< 50 mm
Pressure
10 bar 50 bar
(145 psig) (725 psig)
0.22 % 1.2 %
0.13 % 0.74 %
0.08 % 0.52 %
0.10 % 0.61 %
0.05 % 0.37 %
0.03 % 0.25 %
- -
2.1 % -
1.44 % 9.2 %
1.01 % 5.7 %
K-band (26 GHz technology)
3
100 bar 200 bar
(1450 psig) (2900 psig)
2.4 % 4.9 %
1.5 % 3 %
1.1 % 2.1 %
1.2 % 2.5 %
0.76 % 1.6 %
0.53 % 1,1 %
- -
- -
- -
13.2 % 76 %
VEGAPULS 62 • Profibus PA