Dräger PIR 7000 Technical Handbook page 22

Assembly and Installation
Figure 3:
Range of permissible signal loop impedance for devices in HART
depending on supply voltage
600
500
400
300
200
100
0
0
22
permissible impedance range of the signal loop
during HART multidrop operation
min. 230 Ω at 9 V
max. 500 Ω at 9 V
5 10 15
supply voltage at the terminals of the gas transmitter [V]
®
multidrop operation,
min. 230 Ω at 30 V
max. 500 Ω at 30 V
20 25 30 35