4–20 mA Loop Check
Loop
Voltage budget
2-wire loop: U_tx = U_supply − U_barrier − I · (R_load + R_cable). Copper 0.0175 Ω·mm²/m at 20 °C, +0.393 %/K. Take the minimum voltage from the transmitter data sheet (with HART it is usually higher).
2-wire loop: U_tx = U_supply − U_barrier − I · (R_load + R_cable). Copper 0.0175 Ω·mm²/m at 20 °C, +0.393 %/K. Take the minimum voltage from the transmitter data sheet (with HART it is usually higher).