4-20 mA Loop Cheat Sheet (PDF)

Everything you check on a 4-20 mA loop, on one clear 3-page sheet.

WHAT IS INSIDE

• Scaling table and formulas, with worked examples (mA to reading and back)
• NAMUR NE43 signal limits: what 0 mA, 3.6 mA and 21 mA are telling you
• 2-wire, 3-wire and 4-wire transmitters, and the one rule for loop power
• Loop resistance budget and the HART resistor
• How to measure loop current without breaking the loop
• Symptom and likely cause table, and a commissioning checklist

WHO IT IS FOR

Electricians, instrument and automation techs, and apprentices.

WHAT YOU GET

One PDF, A4 size, instant download after payment.

GOOD TO KNOW

• General training, not design advice. Follow the manufacturer's manual and the rules where you work.
• For personal use. Please do not share or resell the file.

Made by Basic Sparky: PLCs and automation, made simple. Free scaling calculator at app.basicsparky.com.