Welch Allyn CP150 12-Lead Resting Electrocardiograph, Software Version 2.00.XX - Quick Reference Guide - Manual (Page 15)

Lead alert or square wave
A dot might be flashing on the lead-status screen. Or one or more leads might appear as
a square wave.
Causes
•
Electrode contact might be poor.
• A lead might be loose.
• A lead might be defective.
Actions
•
Replace the electrode.
• Verify that the patient’s skin has been properly prepared.
• Verify that electrodes have been properly stored and handled.
• Replace the patient cable.
Quick reference guide Troubleshooting 13