Siemens 7ML5431 - Curve 1 (General Purpose, Intrinsically Safe, Non-Sparking, Non-Incendive); Curve 2 (Flameproof, Increased Safety, Explosion-Proof)

Appendix A: Technical reference
A.6 Loop power
SITRANS LR250 with mA/HART
Operating Instructions, 10/2019, A5E32220602-AG
257
A.6.2 Curve 1 (General Purpose, Intrinsically Safe, Non-Sparking, Non-incendive)
Loop Voltage versus Loop Resistance
Note
When using HART communications, the minimum voltage with 220 Ohms (RL) is
16.3 V DC.
A.6.3 Curve 2 (Flameproof, Increased Safety, Explosion-proof)
Loop Voltage versus Loop Resistance
Note
When using HART communications, the minimum voltage with 220 Ohms (RL) is 20.94 V
DC.