The system translates a physical measurement (like pressure or temperature) into a current signal between 4 mA and 20 mA. Represents the 0% or minimum value of the range. 20 mA: Represents the 100% or maximum value of the range.
Handles power-hungry sensors (e.g., gas detectors). 4-Wire Connection (Fully Isolated)
I=4mA+(16mA×P)cap I equals 4 m cap A plus open paren 16 m cap A cross cap P close paren Example: At 50% capacity, the loop should read . If you are designing a specific circuit, let me know: The sensor type you are using. The distance between the sensor and the controller. shema tokovaja petlja 4 20 ma
Current signals are less affected by electromagnetic interference (EMI) than voltage signals.
Converts the sensor signal into the 4-20 mA current. The system translates a physical measurement (like pressure
If the wire snaps, the current hits 0 mA, immediately triggering a "fault" alarm.
A device like a PLC or indicator that reads the signal, usually by passing the current through a 250 Ohm resistor to create a 1-5V drop for processing. 📐 Connection Types (Wiring Schemes) 2-Wire Connection (Passive) Handles power-hungry sensors (e
The 4 mA floor allows the system to distinguish between a "zero" reading and a broken wire (0 mA). 🛠️ Main Components A functional circuit consists of four essential parts: Sensor/Transducer: Measures the physical variable.