To come up against an electric cable while drilling a hole in a wall can have catastrophic consequences. Likewise, drilling into gas, water pipes or central heating pipes can be extremely hazardous. With a handy metal detector it can now be determined beforehand whether there are metal objects to be found in a wall, ceiling or floor.
An LED indicates if a metal object is in the vicinity. If an audio signal is also desired, space has been provided on the PCB for buzzer type SV4/12-S to be connected. The PCB has been specially constructed to fit entirely into to the separately available box type G407.
The coil consists of two windings around the ferrite core supplied. In order to facilitate winding, thin double sided sticky tape can be stuck to the ferrite core, each winding can be held down using ordinary sellotape. Both windings must be wound in the same direction.