Vega VEGAPULS 62 Operating Instructions Manual page 72

11 Supplement
10 mm (0.394 in)
2 mm (0.079 in)
0
- 2 mm (- 0.079 in)
- 10 mm (- 0.394 in)
Fig. 51: Deviation under reference conditions
1 Reference plane
2 Antenna edge
3 Recommended measuring range
Repeatability
Deviation with bulk solids
Variables influencing measurement accuracy
Specifications apply to the digital measured value
Temperature drift - Digital output
Additional deviation through electromag-
netic interference acc. to EN 61326
Specifications apply also to the current output
Temperature drift - Current output
Deviation on the current output through analogue/digital conversion
Ʋ Non-Ex and Ex-ia version
Ʋ Ex-d-ia version
Deviation in the current output due to
strong, high-frequency electromagnetic
fields acc. to EN 61326
Influence of the superimposed gas and pressure to the 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 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.
72
0,5 m (1.6 ft)
1 2
≤ ±1 mm
The values depend to a great extent on the application.
Binding specifications are thus not possible.
±3 mm/10 K, max. 10 mm
< ±50 mm
±0.03 %/10 K relating to the 16 mA span max. ±0.3 %
< ±15 µA
< ±40 µA
< ±150 µA
VEGAPULS 62 • 4 ... 20 mA/HART - four-wire
3