VEGA VEGAPULS 68 (≥ 2.0.0 - ≥ 4.0.0) Foundation Fieldbus User Manual
Page 65
65
11 Supplement
VEGAPULS 68 • Foundation Fieldbus
36538-EN-121011
Resolution, digital
> 1 mm (0.039 in)
Accuracy (according to DIN EN 60770-1)
Process reference conditions according to DIN EN 61298-1
Ʋ Temperature
+18 … +30 °C (+64 … +86 °F)
Ʋ Relative humidity
45 … 75 %
Ʋ Air pressure
860 … 1060 mbar/86 … 106 kPa (12.5 … 15.4 psig)
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
1,0 m (3.28 ft)
10 mm (0.394 in)
2 mm (0.079 in)
- 2 mm (- 0.079 in)
- 10 mm (- 0.394 in)
0
1 2
3
Fig. 53: Deviation under reference conditions
1 Reference plane
2 Antenna edge
3 Recommended measuring range
Reproducibility
≤ ±1 mm
Deviation with bulk solids
The values depend to a great extent on the application.
Binding specifications are thus not possible.
Deviation under EMC influence
≤ ±30 mm
Variables influencing measurement accuracy
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
Characteristics and performance data
Measuring frequency
K-band (26 GHz technology)
Measuring cycle time approx.
700 ms
Step response time
1)
≤ 3 s
1)
Time span after a sudden measuring distance change by max. 0.5 m in liquid applications, max 2 m with bulk
solids applications, until the output signal has taken for the first time 90 % of the final value (IEC 61298-2).