71
11 Supplement
VEGAPULS SR 68 • 4 … 20 mA/HART two-wire
38294-EN-130624
HART output values according to HART 7.0
1)
Ʋ PV (Primary Value)
Distance to the level
Ʋ SV (Secondary Value)
Level as percentage value
Ʋ TV (Third Value)
Linearised percentage value
Ʋ QV (Fourth Value)
Scaled measured value
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
Biggest false signal, 20 dB smaller than the useful signal
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. 56: Deviation under reference conditions
1 Reference plane
2 Antenna edge
3 Recommended measuring range
Repeatability
≤ ±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
Specifications apply to the digital measured value
Temperature drift - Digital output
±3 mm/10 K relating to the max. measuring range or
max. 10 mm
Additional deviation through electromag-
netic interference acc. to EN 61326
< ±50 mm
1)
Default values, can be assigned individually
