I use non contact voltage tester function of Uni-t ut210e for detecting main wires under/in walls. It worked pretty well until yesterday.
The wall is made of bricks/mortar and some metal profiles (as I experienced today when drilling holes for wall shelf). There is 0 voltage between that metal profile and the ground.
Also, there is a wall socket 20 cm from the bottom of the wall. Mains voltage is 230 V.
What could be the cause of NCV meter beeping over almost entire wall?
Best Answer
When the batteries start to run down this can cause the filters not to work which can result in erratic sounding. Also the electronics also go bad. this can cause erratic sounding. They are mass produced and don't always have a long life.