VEGA VEGABAR 51 Foundation Fieldbus - Manual (Page 49)

49
10 Supplement
VEGABAR 51 • Foundation Fieldbus
36715-EN-130321
Ʋ Air pressure 860 … 1060 mbar/86 … 106 kPa (12.5 … 15.4 psi)
Determination of characteristics Limit point adjustment according to IEC 61298-2
Characterstic curve Linear
Reference installation position upright, diaphragm points downward
Influence of the installation position depending on the chemical seal version
Deviation determined according to the limit point method according to IEC 60770 10)
Applies to the digital signal output (HART, Profibus PA, Foundation Fieldbus) as well as to ana-
logue current output 4 … 20 mA and refers to the set span. Turn down (TD) is the ratio nominal
measuring range/set span.
Deviation
Ʋ Turn down 1 : 1 < 0.2 %
Ʋ Turn down up to 5 : 1 < 0.2 %
Ʋ Turn down up to 10 : 1 < 0.3 %
Influence of the product or ambient temperature
Thermal change zero signal and output span
Applies to the digital signal output (HART, Profibus PA, Foundation Fieldbus) as well as to ana-
logue current output 4 … 20 mA and refers to the set span. Turn down (TD) is the ratio nominal
measuring range/set span.
Thermal change zero signal and output span, reference temperature 20 °C (68 °F):
Ʋ In the compensated temperature
range 0 … +100 °C (+32 … +212 °F)
< 0.05 %/10 K x TD
Ʋ Outside the compensated tempera-
ture range
typ. < 0.05 %/10 K x TD
Thermal change, current output
Applies also to the analogue 4 … 20 mA current output and refers to the set span.
Thermal change, current output
< 0.05 %/10 K, max. < 0.15 %, each with -40 … +80 °C
(-40 … +176 °F)
0,15 %
-0,15 %
-40°C -20°C
20°C
40°C 60°C 80°C
Fig. 27: Thermal change, current output
10) Incl. non-linearity, hysteresis and non-repeatability.