VEGA VEGABAR 51 4 … 20 mA_HART - Manual (Page 50)

50
10 Supplement
VEGABAR 51 • 4 … 20 mA/HART
36713-EN-130321
Ʋ Primary Value Pressure
Ʋ Secondary Value Temperature 9)
Signal resolution 1.6 µA
Failure signal current output (adjustable) mA-value unchanged 20.5 mA, 22 mA, < 3.6 mA
Max. output current
22 mA
Load see load diagram under Power supply
Met NAMUR recommendation NE 43
Dynamic behaviour output
Run-up time approx.
10 s
90 %
100 %
10 %
t
t
T A
t
t
S
2 1
Fig. 27: Sudden change of the process variable, dead time t
T
, rise time t
A
and step response time t
S
1 Process variable
2 Output signal
Dead time ≤ 150 ms
Rise time ≤ 100 ms (10 … 90 %)
Step response time ≤ 250 ms (ti: 0 s, 10 … 90 %)
To this amounts the reaction time of the isolatng system. This time varies from values < 1 s with
compact chemical seals to several seconds with capillary systems.
Example: Flange-type chemical seal DN 80, filling silicone oil KN 2.2, capillary length 10 m, meas-
uring range 1 bar
Process temperature Reaction time
40 °C approx. 2 s
20 °C approx. 3 s
-20 °C approx. 11 s
Damping (63 % of the input variable) 0 … 999 s, adjustable
Input variable
Adjustment
Adjustment range of the min./max. adjustment relating to the nominal measuring range:
9) Depending on the respective instrument and the process fitting, the temperature can deviate from the real
process temperature.