3M 725 Wrist Strap Monitor Instructions, introduces the operation principle, installation method and maintenance method of the wrist strap monitor.
This manual explains how the 3M Model 725 Wrist Strap Monitor works, including the theory of operation that measures resistance through the wrist‑strap loop and the ground‑clip loop. It details the resistance thresholds that trigger visual and audible alarms and describes how to verify proper grounding of both the operator and work surfaces.
Installation instructions cover attaching the monitor to static‑control work surfaces, mounting under a work bench, using belt clips, and optional accessories. Battery replacement, low‑battery warnings, and warranty information are also included.
| Ground‑clip loop resistance threshold | Alarm if > 10 MΩ |
|---|---|
| Battery voltage low‑warning level | 6 V |
| Battery life (continuous operation) | Approximately 1 year |
| Power source | 9 V battery |
| Current consumption during alarm | ≈ 5 pA |
| Current consumption in normal condition | ≈ 50 µA |
The monitor alarms (red lamp and audible tone) when the wrist‑strap loop resistance exceeds 35 megohms.
The battery is expected to last about one year of continuous operation under normal conditions.
When the battery voltage drops below 6 volts the red lamp illuminates to warn the user.