Vega VEGAPULS 21 - Deviation specifications and accuracy factors

47
14 Supplement
VEGAPULS 21 • Two-wire 4 … 20 mA/HART
58351-EN-191014
Deviation (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 Distance to installations > 200 mm (7.874 in)
Ʋ Reector Flatplatereector
Ʋ Falsereections Biggest false signal, 20 dB smaller than the useful signal
Deviation with liquids ≤2mm(meas.distance>0.25m/0.8202ft)
Non-repeatability
7)
≤2mm
Deviation with bulk solids The values depend to a great extent on the application.
Bindingspecicationsarethusnotpossible.
0,25 m (0.8202 ft)
10 mm (0.3937 in)
- 10 mm (- 0.3937 in)
2 mm (0.079 in)
- 2 mm (- 0.079 in)
0
1
2
3
Fig. 28: Deviation under reference conditions
1 Antennaedge,referenceplane
2 Recommended measuring range
Variablesinuencingmeasurementaccuracy
Specicationsapplytothedigitalmeasuredvalue
Temperature drift - Digital output < 3 mm/10 K, max. 10 mm
Specicationsapplyalsotothecurrentoutput
Temperature drift - Current output < 0.03 %/10 K or max. 0.3 % relating to the 16.7 mA
span
Deviation in the current output due to
digital/analogue conversion
< 15 µA
Additional deviation through electromagnetic interference
Ʋ According to NAMUR NE 21 < 80 µA
Ʋ According to EN 61326-1 None
Ʋ According to IACS E10 (shipbuilding)/
IEC 60945
< 250 µA
7)
Already included in the meas. deviation