From Unknown PIR to Dual TEC

[GalaxyGuy]

1 hour ago, RayPooley said:

Here's the thing. A basic PIR only detects infra read heat. Right? In particular infra red radiation that is above that of the surrounding environment. Furthermore, having tested mine, they only trigger when that "hot spot" is moving. They are basically motion sensors. The same as the technology I have in the toilets that turn the lights on when someone walks in.  And loose bricks tend to be at ambient temperature. So I wouldn't expect a basic PIR to detect a flying brick unless the brick had been basking in the sun so that it was significantly hotter than the space around it. But that's a bit hit and miss. So I am looking for something that doesn't rely on infra red radiation. That's why I have gone for the Dual TEC infra red and microwave technology. 

 

Yes, the pyroelectric sensor detects infra red radiation.  It also detects the pattern of the surrounding ambient environment.  If a flying object manages to disrupt that environment across the planes/zones, then the device will trigger.  The closer the object is to the element, then the bigger the disruption to the planes/zones. So, a flying object that doesn't perfectly match the background temp of each plane/zone can trigger the PIR. The object doesn't need to be hot, just not a match for each individual plane/zone.  As above, still not a reliable detection method.

 

You've gone for a dual tec, but probably wanted a microwave only or multi-beam active IR detector, as dual-tec devices will not trigger on microwave detection alone.

 

 

[RayPooley]

5 minutes ago, al-yeti said:

Ok so then pay for monitored CCTV 

I have CCTV. All around the perimeter. The police have the footage. You know what they can do? Nothing. Because it's kids and kids are untouchable.

6 minutes ago, MrHappy said:

 

google Ray & he his own web page with name, address, life history, mobile no. ect...

 

Isn't it a data protection issue to be posting IP no's ? 

No. Checkout WhatIsMyIpAddress.com and others.

[RayPooley]

5 minutes ago, MrHappy said:

What colour horse did your alarm installer ride?

 

For less than a grand I could have done you a proper alarm with sensors on their own zones & tamper circuits...

That's nice of you but you're too far away.

[petrolhead]

Monitored cctv signalling on movement on the internal cams would have done what you want though, the monitoring station would call you to alert you to the incident. If you had external detection and a pa speaker they might have warned them off.

[RayPooley]

5 minutes ago, GalaxyGuy said:

 

Yes, the pyroelectric sensor detects infra red radiation.  It also detects the pattern of the surrounding ambient environment.  If a flying object manages to disrupt that environment across the planes/zones, then the device will trigger.  The closer the object is to the element, then the bigger the disruption to the planes/zones. So, a flying object that doesn't perfectly match the background temp of each plane/zone can trigger the PIR. The object doesn't need to be hot, just not a match for each individual plane/zone.  As above, still not a reliable detection method.

 

You've gone for a dual tec, but probably wanted a microwave only or multi-beam active IR detector, as dual-tec devices will not trigger on microwave detection alone.

 

 

Thanks GalaxyGuy. Now that's an answer. I appreciate it.

[RayPooley]

7 minutes ago, petrolhead said:

Monitored cctv signalling on movement on the internal cams would have done what you want though, the monitoring station would call you to alert you to the incident. If you had external detection and a pa speaker they might have warned them off.

The actual hurling of the brick through the window took 4.7 seconds from the instant the hurler emerged from the darkness to the instant he disappeared back into it. Even with the best remote monitoring service in the world the brick would still end up through the window. The outcome would be the same. So a monitoring service is no obstacle to a flying brick. The question is one of awareness so that someone can attend. There is nothing faster than an auto dial that can send you a text as soon as the alarm triggers.  But if the  alarm doesn't trigger that's a bit of a spanner in the works. That's the problem I am addressing.

Edited August 14, 2017 by RayPooley

[petrolhead]

You seem to have a smart answer for everything. Good luck with your cafe.

[MrHappy]

 

 

4 minutes ago, RayPooley said:

The actual hurling of the brick through the window took 4.7 seconds from the instant the hurler emerged from the darkness to the instant he disappeared back into it.

 

Is L22 rough ?

[RayPooley]

2 minutes ago, petrolhead said:

You seem to have a smart answer for everything. Good luck with your cafe.

The cafe has been running for two and a half years and is doing very well indeed. Apart from a few niggles like this one.

2 minutes ago, MrHappy said:

 

 

 

Is L22 rough ?

My postcode is on my website.

[sixwheeledbeast]

Did I follow this correctly? A grand for that shoddy work?

 

Movement detectors are designed to detect people walking across them, yes they can pick up other things due to how they work but that's what they are designed to do.

You shouldn't be expecting a PIR or DT to detect this type of incident

There is more to alarms than sticking coloured wires in holes, understanding how detection works and what type you need for the environment is all part of the job.

 

If you want to detect the window being put in, I suggest using a method capable of this. 

Also to your last point an auto dialler maybe fast but it's certainly not a secure method.