VEGA VEGABAR 66 4 … 20 mA_HART - Manual (Page 58)

58
10 Supplement
VEGABAR 66 • 4 ... 20 mA/HART
36737-EN-130321
Deviation determined according to the limit point method according to IEC 60770 12)
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 up to 5 : 1 < 0.1 %
Ʋ Turn down > 5 : 1 < 0.02 % x TD
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. 33: Thermal change, current output
Long-term stability (according to DIN 16086 and IEC 60770-1)
Applies to digital HART interface as well as to analogue current output 4 … 20 mA under refer-
ence conditions. Specifications refer to the set span. Turn down (TD) is the relation nominal meas-
uring range/set span.
Long-term drift of the zero signal:
Ʋ For one year < 0.05 % x TD
Ʋ For five years < 0.1 % x TD
Ʋ For ten years < 0.2 % x TD
12) Incl. non-linearity, hysteresis and non-repeatability.