What kind of sensor did I see today?

It's called finewire...it was used before the invention of motions, glassbreaks, and shock detectors.

Jim Rojas

Jim, Would the design call for the fine wire to break, or would it become taught and pull or tug a sensor? What do you figure the era would be? I am guessing mid 50's to early 60's? Just a guess. Thanks!

J.

Lacing an overhead door is still a reliable means of protecting it. The alarm is already sounding before the perp has a chance to wiggle through the hole he made.

Yes, it is designed to break. I have no idea when it was first used.

Jim Rojas

Did you ever hear of it refered to as "Angel Hair"? It may be that people have their own names for things. Some years ago, we used it to do some metal grates that were in an area not condusive to the installation of electronics. Still working. Simple but effective.

I never heard that word used. We use it for many low cost applications.

I do remember using insulated nails to run a pattern across huge skylights. Eveything was done to UL Mercantile standards. 1 nail every 4 inches, then you had to alternate the positive & negative leads to deter bypassing of loops.

We did AC vents using a thin aluminum tube, which was held in place by electrical tape or a clamp. It was as thin as auto brake lines.

Jim Rojas

We used to call it lacing wire, and oft-times it also had pull-outs at one or both ends. We used to use it to lace skylights and put in attics, crawlspaces, etc.

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The wire is very easy to break (which also makes it a pain to install).

I've laced vulnerable walls before but it's mostly used for overhead and man doors. It's a pain to install (almost as bad as window foil). Photo beams can be compromised if they're not installed properly (mounted too high or too low). In addition in a warehouse environment, it's far too easy to "park" something in front of them. In once instance, a customer had to call his warehouse guy back to move a pallet of goods, but all too often people are in a "rush" to leave and will simply bypass the affected zone (which sort of defeats the purpose of having it there, don'tcha think)?

Yes. They used to "lace" doors and vent openings with this wire and that is exactly how it worked. The problem is the stuff is easy to break and can require a lot of maintenance. Some installers used to make basswood (no relation to this writer:)) screens to protect openings. The basswood dowels are light but not particularly flexible. The wires were embedded in a slot that ran the length of each piece of woord. A thief would have to break or dislodge the screen to get in. Doing so broke the circuit.

These wire lacing schemes are not too common but you'll run into them from time to time. Some of them are still in use. For certain types of openings the wire lace is still effective.

Lacing wire goes back to the 1800's When Edwin Holmes was doing alarm installations. Up until about the mid to late 70's, photoelectric beams were large devices using automobile bayonet style light bulbs, projecting visible light through a glass lens. They used a lot of power and the only way standby capability was available was to use a motorcycle or automobile battery. However, there weren't any small sized battery chargers so the battery had to be manually charged on a periodic basis. Therefore, most people didn't have standby batteries, so during a power failure the alarm would trip. The Ademco 1200 and

1300 I think were the most popular. It wasn't until the Galium Arsnide (?) elements were developed that allowed a solid state PE device with an infrared pulsed signal and a much smaller unit with standby capability.

Other than the uses that have already been described to you, there was also a wire called trap wire. This was a thin insulated, flexable, stranded wire that was used on pull traps. This was called a "live" trap versus a pull trap that just used a string of some sort, which was referred to as a "dead" trap. The live trap would trip the alarm if someone either cut or pulled the trap. The dead trap only worked if the clip was pulled out. See Ademco number 72 pull trap. I don't think the UL live traps are made anymore. Sometimes the solid lacing wire was substituted for the trap wire. Not what it was meant for, but sometimes you'll find it used for traps too. There was also much wider foil too. This was used on doors mostly. The wide foil was applied to a piece of masonite and then the masonite was attached to the inside of the door.

Very occasionally, I'll still use trap wire if I'm doing an old house with the old fasioned wooden basement windows. Especially if they're painted closed, nailed shut, etc and the only way in is to break through the three panes of glass. I just may have the last roll of trap wire in existance. :-)

The thin wire that was used to construct basswood screens was an uninsulated bare copper wire. I think I may still have a roll of that stashed away somewhere too.

Sounds like you came across old time lace wiring. It was used years ago. Just a closed circuit laced like a shoe but the wires crossed with positive and negative single wires. If broken the circuit would open or if they crossed they shorted and tripped the alarm. As far as using a ceiling detector many different detectors are not UL rated for Burglary (Central, Police Connect, Local or the "Extent" coverage rating. Check with Underwriter's Laboratories about ratings. These are different than an electrical rating.

Pat Burke Alarm Lease and Service New York, New York

P.S. Some of us aren't old, just very experienced. No offense taken, 36 years in the trade. Join your local Alarm Association. Past President, Metropolitan Burglar & Fire Alarm Association

SecurityNovice wrote:

This is what I love about this news group.. there is such a wealth of knowledge available.. Much appreciated! Maybe I am just too anal, but I find designing a system to be a challenge.. requiring a lot of thought and most of all, having a good working knowledge of what equipment is available from vendors and how to apply it correctly. I wish I could work for an old timer for a year or two and learn the trade.. Honestly, I learn as I go.. and I know at times at the expense of the customer. I wish I could go back and suggest to a few.. maybe I should have angled that PIR a little further away from the heat duct... etc.. Thanks a lot guys.. Great info. I took a black and white picture of the laced door before it went in the dumpster..

interesting

One of the earliest applications for lacing wire was the protection of safes. I believe it was Holmes who pioneered the use of the safe cabinet, a custom-built wooden cabinet that surrounded the safe. Penetrating the walls of the cabinet resulted in a broken wire, causing an alarm before the burglar even reached the safe.

Safe cabinets were still used up through the 1950s and even later, sometimes with foil linings instead of lacing wire. The cost of construction made them unattractive, as did the availability of electronic safe protection systems.

I think it was Arrowhead that introduced the first solid-state photocells in the early 1970s. But I do remember the old beams with light bulbs inside, complete with a spinning metal disk with holes in it to "modulate" the beam.

- badenov

Jebuz.. you and Jim are OLD!!!!!

You can and should do such things, friend. As your business begins to grow you can keep your older customers and earn lots of referrals by visiting them from time to time. If you see something that you did earlier that could have been done a little better, offer to adjust it as a courtesy -- especially anything that has caused a false alarm.

I used to try to visit every client at least once a year regardless if they were under a service contract (most were not). I'd just stop in to check on the system and make sure they were using it and weren't experiencing any problems. If I saw something minor that needed fixing I'd do it free on the spot. Those courtesy visits paid off in referrals and long-term service relationships.

As my business grew it eventually became impossible to visit every customer for free but I tried to stay in touch with them all. We billed annually for monitoring service so I used to call each customer the day before we'd send out their invoice. Those calls helped keep our attrition rate extremely low.

Best of luck.

woord, woord , woord, woord,woord, woord , woord, woord,woord, woord , woord, woord

DID HE MEAN WOOD - LIKE HIS HEAD?

To forgot to mention the oil bath motors that spun that metal disk :)

In ADT it was called geon