VEGA VEGAPULS WL 61 4 … 20 mA_HART - two-wire - Manual (Page 46)

46
11 Supplement
VEGAPULS WL 61 • 4 … 20 mA/HART - two-wire
38061-EN-121011
Installation reference conditions
Ʋ Min. distance to installations > 200 mm (7.874 in)
Ʋ Reflector Plane plate reflector
Ʋ False reflections Largest false echo 20 dB smaller than the useful echo
Deviation with liquids See following diagrams
0,5 m (1.6 ft)
10 mm (0.394 in)
- 10 mm (- 0.394 in)
2 mm (0.079 in)
- 2 mm (- 0.079 in)
0
1 2 3
Fig. 45: Deviation under reference conditions
1 Reference plane
2 Antenna edge
3 Recommended measuring range
Reproducibility ≤ ±1 mm
Variables influencing measurement accuracy
Specifications apply to the HART signal and the current output
Temperature drift - Digital output
±3 mm/10 K relating to the max. measuring range or
max. 10 mm
Additional deviation through strong, high
frequency electromagnetic fields acc. to
EN 61326
< ±50 mm
Specifications apply also to the current output
Temperature drift - Current output
±0.03 %/10 K relating to the 16 mA span max. ±0.3 %
Deviation on the current output by ana-
logue/digital conversion
< ±15 µA
Deviation on the current output due to
strong, high frequency electromagnetic
fields acc. to EN 61326
< ±150 µA
Characteristics and performance data
Measuring frequency
K-band (26 GHz technology)
Measuring cycle time approx. 450 ms
Step response time 2) ≤ 3 s
2) Time span after a sudden distance change of max. 0.5 m until the output signal reaches for the first time 90% of
the final value (IEC 61298-2).