Good morning,

Following an unfortunate incident where I drilled through a cable, I
am looking for a slightly better detector than the zircon stud
detector that I was using at the time (before you ask - I did have it
set to AC rather than wood and the cable was only just below the
surface)!

I thought Zircons were supposed to be the best for stud detection but
IME it hasn't been very useful.

What do you recommend for voltage (domestic AC) detection and what
about metal detection for avoiding pipes? Are the brand names more
reliable than the no-names?

What about these no contact voltage pens? Are they any good for
finding wires in walls?

TIA,
Fred

Fred wrote :
What about these no contact voltage pens? Are they any good for
finding wires in walls?

Probably as good as your Zircon = useless.

The cable has to be very close to the surface and with the live wire
nearest the voltstick (voltage pen). The larger the live surface area,
the further away it can be detected.

Despite the above, well worth having one in your tool box for their
intended use - get a Fluke voltstick, they are the best one I have
found.

--
Regards,
Harry (M1BYT) (L)
http://www.ukradioamateur.co.uk

Back in the 60s, I used a converted old hearing aid with a coil on a bit of
wire to detect the hum from a mains cable as it wandered around a wall. it
worked better than I expected,indeed, better still if a load was on the
other end of the cable at the time. I don't know how these new fangled
devices work, but it may well be that if a load is on said cable, the
magnetic flux around the wire will be easier to detect.
Brian

--
Brian Gaff -
Note:- In order to reduce spam, any email without 'Brian Gaff'
in the display name may be lost.
Blind user, so no pictures please!
"Harry Bloomfield" wrote in message
. uk...
Fred wrote :
What about these no contact voltage pens? Are they any good for
finding wires in walls?

Probably as good as your Zircon = useless.

The cable has to be very close to the surface and with the live wire
nearest the voltstick (voltage pen). The larger the live surface area, the
further away it can be detected.

Despite the above, well worth having one in your tool box for their
intended use - get a Fluke voltstick, they are the best one I have found.

--
Regards,
Harry (M1BYT) (L)
http://www.ukradioamateur.co.uk

Brian Gaff laid this down on his screen :
I don't know how these new fangled devices work, but it may well be that if a
load is on said cable, the magnetic flux around the wire will be easier to
detect.

They will detect a live wire end with no current flowing, so I would
guess they must work via capacitive detection rather than magnetic.

--
Regards,
Harry (M1BYT) (L)
http://www.ukradioamateur.co.uk

Fred wrote:

Good morning,

Following an unfortunate incident where I drilled through a cable, I
am looking for a slightly better detector than the zircon stud
detector that I was using at the time (before you ask - I did have it
set to AC rather than wood and the cable was only just below the
surface)!

I thought Zircons were supposed to be the best for stud detection but
IME it hasn't been very useful.

What do you recommend for voltage (domestic AC) detection and what
about metal detection for avoiding pipes? Are the brand names more
reliable than the no-names?

What about these no contact voltage pens? Are they any good for
finding wires in walls?

TIA,
Fred

Just triued my Fluke voltstick. My cables are under 1/4"-3/4" plaster inside
oval conduit and some in round. I know exactly where they are because I put
them there. No foil lined plasterboard - just regular plaster on brick.

The Fluke has two indications - red=very strong and blue=near and the flush
pulsates with a frequency related to E-field strength.

Result

1) 3/4" deep - zero indication.

2) 1/4-1/2" deep - some slow pulsating blue, flashing fastest dead center of
cable.

Conclusion - if it can see the cable at all, I would give it +/- 2" for
locational accuracy.

It is highly likely to miss deeper cables. Ifyou have plasterboard, or
worse, foil backed PB, forget it.

It's not what voltsticks ar edesogned for - they are for detecting very
short range E-fields through a bit of plastic.

HTH

Tim

--
Tim Watts

Harry Bloomfield wrote:

Brian Gaff laid this down on his screen :
I don't know how these new fangled devices work, but it may well be that
if a load is on said cable, the magnetic flux around the wire will be
easier to detect.

They will detect a live wire end with no current flowing, so I would
guess they must work via capacitive detection rather than magnetic.


Yep - they detect electric fields not magnetic. Static sets them off too -
eg rubbing the tip over matt emulsion will cause it to flash.

--
Tim Watts

On Sun, 30 Oct 2011 12:50:11 +0000, Tim Watts
wrote:


It's not what voltsticks ar edesogned for - they are for detecting very
short range E-fields through a bit of plastic.

Thanks for experimenting. They were just one thought I had. What about
other devices, such as these:

http://www.screwfix.com/p/stanley-de...l-sensor/49740

which has poor reviews, or

http://www.screwfix.com/p/bosch-pd06...detector/37920

or any similar device?

TIA,
Fred

On Sun, 30 Oct 2011 10:04:15 +0000, Fred
wrote:

What about these no contact voltage pens? Are they any good for
finding wires in walls?

I had one that was far too sensitive for use in a junction box, but
would have been excellent for finding buried cables. It would light up
at least 50mm from a live cable. It was replaced by a Fluke jobbie
that only lights within a couple of mmm of a cable.

Fred wrote:

Good morning,

Following an unfortunate incident where I drilled through a cable, I
am looking for a slightly better detector than the zircon stud
detector that I was using at the time (before you ask - I did have it
set to AC rather than wood and the cable was only just below the
surface)!

I thought Zircons were supposed to be the best for stud detection but
IME it hasn't been very useful.

What do you recommend for voltage (domestic AC) detection and what
about metal detection for avoiding pipes? Are the brand names more
reliable than the no-names?

What about these no contact voltage pens? Are they any good for
finding wires in walls?

I have one similar to this
http://www.screwfix.com/p/megger-vf1...ector-pen/2393
2 but coloured yellow ... Excellent at checking if the mains is on at a
plug, socket or along a cable/wire .. I doubt I'd trust it on a cable
buried in the wall, though I've never tried .. might give it a test
later!

--
Paul - xxx
"You know, all I wanna do is race .. and all I wanna do is win"
Mark Cavendish, World Champion 2011.

On 30/10/2011 14:44, Fred wrote:
On Sun, 30 Oct 2011 12:50:11 +0000, Tim
wrote:


It's not what voltsticks ar edesogned for - they are for detecting very
short range E-fields through a bit of plastic.

Thanks for experimenting. They were just one thought I had. What about
other devices, such as these:

http://www.screwfix.com/p/stanley-de...l-sensor/49740

which has poor reviews, or

Where did you find the reviews Fred?

--
Dave - The Medway Handyman www.medwayhandyman.co.uk

The Medway Handyman wrote:
On 30/10/2011 14:44, Fred wrote:
On Sun, 30 Oct 2011 12:50:11 +0000, Tim
wrote:


It's not what voltsticks ar edesogned for - they are for detecting
very short range E-fields through a bit of plastic.

Thanks for experimenting. They were just one thought I had. What
about other devices, such as these:

http://www.screwfix.com/p/stanley-de...l-sensor/49740

which has poor reviews, or

Where did you find the reviews Fred?

On the link that he gave, in the bit that said "product reviews"?

Just a guess:-)


--
Adam

On Sun, 30 Oct 2011 16:23:27 -0000, "ARWadsworth"
wrote:


On the link that he gave, in the bit that said "product reviews"?

Just a guess:-)

You guessed right

On 30 Oct 2011 15:38:15 GMT, "Paul - xxx"
wrote:


I have one similar to this
http://www.screwfix.com/p/megger-vf1...ctor-pen/23932 but coloured yellow ... Excellent at checking if the mains is on at a
plug, socket or along a cable/wire .. I doubt I'd trust it on a cable
buried in the wall, though I've never tried .. might give it a test
later!

That's exactly the same as I had, that went too sensitive for normal
use.

Well that is no good is it. it would not be expensive to build both kinds of
detector into a unit I'd have thought.
Brian

--
Brian Gaff -
Note:- In order to reduce spam, any email without 'Brian Gaff'
in the display name may be lost.
Blind user, so no pictures please!
"Tim Watts" wrote in message
...
Harry Bloomfield wrote:

Brian Gaff laid this down on his screen :
I don't know how these new fangled devices work, but it may well be that
if a load is on said cable, the magnetic flux around the wire will be
easier to detect.

They will detect a live wire end with no current flowing, so I would
guess they must work via capacitive detection rather than magnetic.


Yep - they detect electric fields not magnetic. Static sets them off too -
eg rubbing the tip over matt emulsion will cause it to flash.

--
Tim Watts