5 Common 4–20 mA Mistakes in Field Instrumentation

1. Measuring Current in Parallel

Loop current must always be measured in series.

2. Ignoring Grounding

Poor shielding causes unstable signals.

3. Calibrating Without Loop Check

Wiring issues remain unresolved.

4. Assuming 4 mA Means Fault

4 mA is live zero – not necessarily a problem.

5. Replacing Transmitter Without Diagnosis

The loop tells the truth if measured properly.

👉 Complete troubleshooting guide: Advanced 4–20 mA Troubleshooting