Vega VEGAPULS 62 Operating Instructions Manual page 58

10 mm (0.394 in)
2 mm (0.079 in)
0
- 2 mm (- 0.079 in)
- 10 mm (- 0.394 in)
1 2
Fig. 31: Deviation under reference conditions
1 Reference plane
Antenna edge
2
3 Recommended measuring range
Reproducibility
Deviation with bulk solids
Variables influencing measurement accuracy
Temperature drift
Temperature drift - Digital output
Deviation on the current output by analogue/
digital conversion
Deviation on the current output by strong,
high frequency electromagnetic fields within
EN 61326
Additional deviation through strong, high
frequency electromagnetic fields acc. to EN
61326
Influence of the superimposed gas and pressure to the accuracy
The spreading speed of the radar impulses in gas or vapour above the medium is reduced by high
pressures. This effect depends on the 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 high,
negative values that the measured distance is too small.
VEGAPULS 62 • 4 ... 20 mA/HART two-wire
0,5 m (1.6 ft)
≤ ±1 mm
The values are considerably application-depend-
ent. Firm specifications are hence not possible.
±0.03 %/10 K relating to the 16 mA span max.
±0.3 %
±3 mm/10 K relating to the max. measuring range
or max. 10 mm
<±15 µA
<±100 µA
<±50 mm
11 Supplement
3
57