Electric Cable Detector's False Reading and Drilled Through Cable

[greengrass]

bought and used several moons ago a metal/ Electrics detector type you pass over the area on the wall, not pen type.
Tested by passing over a socket and it beeped like mad.
9 " away where I would be drilling, tested, silence, not a squeek. Got drill out 2mins later flash bank wallop, what a picture, what a photograph.
What happened ER indoors exclaimed.
I replied the voltage locator lied. It seems not up to the mark of locating cables at depth of 1.5-2 cm.
I used a friend's Budgie BD725 it shows the whole wall is live beeping everywhere

Q: What is the best buy for DIY home use that's capable of locating in depth. Or reasonable priced professional one?

Foot note: I am very aware electricity takes no prisoners. It was not me being reckless the tester let me down.
Thanks to all in advance.

[Mr White]

Truthful answer? They are all a waste of money.

9/12 22.33

[chriscba]

Cables in walls run vertically & horizontally in line from sockets & switches.
When you drilled 9" away from the socket, was it directly above, below or on either side.

[ericmark]

There are some two part testers which can detect cables buried 2 meters under ground, but most the cheap testers you have to use to trace cable rather than spot check.

So cable from a device like a socket should go vertical or horizontal about best the tester can do is tell you which, even then caught out where a light switch had one vertical and one horizontal even when no safe zone in horizontal direction.

You can get the meters but not at a price that a DIY guy will pay, and even with a RCD you still get a nasty belt even if only for 40 ms.