25
9 Supplement
VEGABAR 18 • Two-wire 4 … 20 mA
55575-EN-200327
90 %
100 %
10 %
t
t
T
A
t
t
S
2
1
Fig. 15: Behaviour the current output in case of sudden change of the process variable. t
T
: dead time; t
A
: rise time;
t
S
: jump response time
1 Process variable
2 Output signal
Size
Time
Dead time
≤ 30 ms
Rise time (10 … 90 %)
approx. 15 ms
Step response time (ti: 0 s, 10 … 90 %)
approx. 45 ms
Reference conditions and influencing variables (according to DIN EN 60770-1)
Reference conditions according to DIN EN 61298-1
Ʋ Temperature
+15 … +25 °C (+59 … +77 °F)
Ʋ Relative humidity
45 … 75 %
Ʋ Air pressure
860 … 1060 mbar/86 … 106 kPa (12.5 … 15.4 psig)
Determination of characteristics
Limit point adjustment according to IEC 61298-2
Characteristic curve
Linear
Reference installation position
upright, diaphragm points downward
Influence of the installation position
< 0.2 mbar/20 Pa (0.003 psig)
Deviation (according to IEC 60770)
3)
Deviation
< 0.5 %
Influence of the medium or ambient temperature
Average temperature coefficient of the
zero signal
4)
< 0.15 %/10 K
Long-term stability (according to DIN 16086)
Long-term drift of the zero signal
5)
< 0.2 %/2 years
3)
Relating to the nominal measuring range, incl. non-linearity, hysteresis and non-reproducibility.
4)
In the compensated temperature range of -40 … +100 °C (-40 … +212 °F), reference temperature 20 °C
(68 °F).
5)
Relating to the nominal measuring range.
