Non-Contact Voltage tester via headset microphone.

1. Connect your wired earphone(with microphone).
2. Hold the microphone of the earphone as shown in photo.
3. When you bring the microphone hole closer to the voltage line, the app will gives warning.
4. The sensitivity of the app and the warning level may differ depending on the phone and earphone.
5. If the app gives warnings for no reason, you can reduce the sensitivity level.