VEGA VEGAFLEX 86 Foundation Fieldbus - Manual (Page 80)

80
11 Supplement
VEGAFLEX 86 • Foundation Fieldbus
44233-EN-130910
Fig. 56: Measuring ranges - VEGAFLEX 86
1 Reference plane
2 Probe length L
3 Measuring range (default setting refers to the measuring range in water)
4 Upper dead band (see diagrams under Accuracy - grey section)
5 Lower dead band (see diagrams under Accuracy - grey section)
Output variable
Output
Ʋ Signal digital output signal, Foundation Fieldbus protocol
Ʋ Physical layer according to IEC 61158-2
Damping (63 % of the input variable) 0 … 999 s, adjustable
Channel Numbers
Ʋ Channel 1 Process value
Ʋ Channel 8 Electronics temperature
Ʋ Channel 9 Count rate
Transmission rate 31.25 Kbit/s
Current value
Ʋ Non-Ex and Ex ia instrument 10 mA, ±0.5 mA
Ʋ Ex-d instruments 16 mA, ±0.5 mA
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 > 500 mm (19.69 in)
Ʋ Vessel metallic, ø 1 m (3.281 ft), centric installation, process
fitting flush with the vessel ceiling
Ʋ Medium Water/Oil (dielectric constant ~2.0) 1)
Ʋ Installation Probe end does not touch the vessel bottom
Sensor parameter adjustment No gating out of false signals carried out
Typical deviation - Interface measure-
ment
± 5 mm (0.197 in)
Typical deviation - Total level interface
measurement
See following diagrams
Typical deviation - Level measurement 2)3) See following diagrams
1) With interface measurement = 2.0
2) Depending on the installation conditions, there can be deviations which can be rectified with an adaptation of
the adjustment or a change of the measured value offset in the DTM service mode
3) The dead bands can be optimizes by a false signal suppression.