VEGA VEGABAR 81 4 … 20 mA - Operating Instructions - Manual (Page 58)

58
11 Supplement
VEGABAR 81 • 4 … 20 mA
45025-EN-131010
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 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 (according to IEC 60770)
Applies to the digital signal output (HART, Profibus PA, Foundation Fieldbus) as well as to the
analogue current output 4 … 20 mA and refers to the set span. Turn down (TD) is the ratio nominal
measuring range/set span.
Accuracy class Non-linearity, hysteresis and re-
peatability with TD 1 : 1 up to 5 : 1
Non-linearity, hysteresis and re-
peatability with 5 : 1
0.2 % < 0.2 % < 0.04 % 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 the
analogue current output 4 … 20 mA and refers to the set span. Turn down (TD) is the ratio nominal
measuring range/set span.
Average temperature coefficient
zero signal
In the compensated tem-
perature range 10 … +70 °C
(+50 … +158 °F)
Outside the compensated tem-
perature range
Turn down 1 : 1 < 0.05 %/10 K typ. < 0.05 %/10 K
Turn down 1 : 1 up to 5 : 1 < 0.1 %/10 K -
Turn down up to 10 : 1 < 0.15 %/10 K -
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. 30: Thermal change, current output