75
11 Supplement
MINITRAC 31 • 4 … 20 mA/HART - four-wire
40447-EN-130430
Switching current
Ʋ
Min.
10 µA
Ʋ
Max.
3 A AC, 1 A DC
Breaking capacity
Ʋ
Min.
50 mW
Ʋ
Max.
750 VA AC, 40 W DC
If inductive loads or stronger currents are switched
through, the gold plating on the relay contact surface will
be permanently damaged. The contact is then no longer
suitable for switching low-level signal circuits.
Contact material (relay contacts)
AgNi or AgSnO and Au plated
Transistor output
Output
Floating transistor output, permanently shortcircuit-proof
Load current
< 400 mA
Voltage loss
< 1 V
Switching voltage
< 55 V DC
Blocking current
< 10 µA
Accuracy (according to DIN EN 60770-1)
Process reference conditions according to DIN EN 61298-1
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 psig)
Repeatability
≤ 0.1 %
Deviation with bulk solids
The values depend to a great extent on the application.
Binding specifications are thus not possible.
Deviation under EMC influence
≤ 1 %
Variables influencing measurement accuracy
Specifications apply to the digital measured value
Temperature drift - HART signal
±0.16 %/10 K relating to the max. measuring range
Specifications apply also to the current output
Temperature drift - Current output
±0.03 %/10 K relating to the 16 mA span max. ±0.3 %
Deviation on the current output by ana-
logue/digital conversion
<±15 µA
Deviation on the current output due to
strong, high frequency electromagnetic
interference acc. to EN 61326
< ±150 µA
Characteristics and performance data
Step response time
5)
≤ 5 s (with damping 1 s)
5)
Time span after a sudden measuring distance change by max. 0.5 m in liquid applications, max 2 m with bulk
solids applications, until the output signal has taken for the first time 90 % of the final value (IEC 61298-2).
