Re: Closed loop embedded in a concrete wall

["Rocky T Squirrel" <gafa_usa@(nospam)hotmail.com>]

sounds like an old "bank night drop"  loop..
first thing  is to run several loops with each end out then make the splices
outside the slab.  that way  you can remove any bad loop later as the ckt
rots out..
if memory serves  several of the old bank service companies use to use a
hard drawn copper in a rubber/pvc jacket. about a 20 ga solid.
If your using a rebar in the concrete then weave the loop in and out of the
rebar but try not to touch the rebar as the concrete is poured..
you could also try and have the concrete supplier to add a lot of flint to
the mix.  will play hell to anyone trying to drill the slab..
and if you really want to go old school  make all the pig tails the same
color..
LOL   makes it a bitch to check loops once the net is set..

RTS



"Beachcomber" <invalid@xxxxxxxxxxxx> wrote in message
news:458fb530.1964234@xxxxxxxxxxxxxxxxxxx
> On Mon, 25 Dec 2006 10:03:25 GMT, Frank Olson
> <Use_the_email_links@xxxxxxxxxxxxxxxxxxxxxx> wrote:
>
> >Beachcomber wrote:
> >> I will have access to a concrete foundation wall space before the pour
> >> and I would like to embed a simple closed loop trip circuit to deter
> >> against the remote possiblity of a break in from the basement.  (This
> >> is a commercial installation.  The wall will be at least 8" thick and
> >> have rebar inside for strength.
> >>
> >> What type of wire/cable would be best?
> >>
> >> Here are my concerns.
> >>
> >> I don't want to use bare copper in the concrete because of
> >> oxidation/deterioration concerns and the possiblility of accidental
> >> grounds.
> >>
> >> The wire or cable should be mechanically thick enough to last a long
> >> time (many many years), but readily break if the wall is attacked with
> >> drilling, sledge hammers, etc.
> >>
> >> What materials would be best for concrete?  Would you use a plastic or
> >> metallic sheath? ...Possibly PVC?
> >>
> >> Any suggestions or advice would be greatly appreciated.
> >>
> >> Beachcomber
> >>
> >>
> >>
> >
> >
> >Yeah...  Vault vibration sensors spaced evenly around the perimeter.  If
> >they do dig through the concrete and happen to "miss" your simple
> >"sensor loop", you're gonna look like a "monkey".  I guess this place
> >must contain the Crown Jewels, or Imelda Marcos's off-shore shoe
collection.
>
> Yeah...Well  Imelda loves her shoes  What can you do?
>
> I looked into a Honeywell vibration detection system for vaults and
> safes.  Expensive... but it does everything apparantly, detects
> seismic disturbances, vibrations and explosions... even prints out a
> log of events.
>
> At the other end of the market are the cheapo vibration detectors that
> require a pulse stretcher, made by Ademco, among others, I think..
>
> I was just looking for some extra protection for the concrete wall...
> sort of like a concealed screen.
>
> Beachcomber
>
>