Volumetric Alarm Systems

[stiggypop]

Hi guys,

I have searched the forums but not found anything relating to Volumetric Alarm Systems. Is this because they are new technology or because they are rubbish?!

As mentioned in my "introduce yourself" post, I have been running a monitored volumetric alarm system for the past couple of years. As a fellow cat owner this has worked a dream as the alarm requires no PIRs and only goes off if a door or window is broken or opened quickly and there is a change in atmospheric pressure (I think!).

I have just had the alarm de-activated as I was incurring a monthly charge of

[james.wilson]

vulumetric means detecting areas of volume, so normal pir's, dt's etc. Also your pressure wave detector would also i suppose come under this group. You wont find much if anything on them because they dont really work well in most environments. In a sealed draft free box they would.... in a house.... rarely.

Depending on the age of the system will depend on the unit you have. I first saw these about 18 yrs ago made by if i recall MP electronics, little grey and black box. More recently it was bought back to life in the Pyronix Veritec... Neither worked IMHO unless the conditions (ie totally sealed box) were perfect.

Im assuming as you were paying monthly you were either on police response or paid a reduced/subsidised install fee

Depending on the box you have will decide if its any use. ALso its age etc.

All the things the require are readily available, but there are words of caution.

1) External siren

2) Connectivity to a smoke/co2 alarm

3) Text messaging alert upon intrusion

4) Number keypad

5) Cat sensative PIRs

1, no problem

2, no problem but you will find they are seperate detectors. Id probbaly look at wireless for this bit as a smoke sensors needs to be high and central as smoke rises, a co2 sensor doesnt as co2 doesnt rise.

3, can work great but id use sms as a backup signalling path for extra info not your only path. HOw many times have you sent a text that never arrived?

4, no problem

5, Im not a fan of pet tolerant sensors. Some sort of work, others dont really work. If you can limit you pets to an area and use 'perimeter' protection, ie vibration sensors and contacts for doors and windows, maybe glass break detection etc. Then in your other areas use conventional movement detection that will not think a burgler is a dog.

James

[Chorlton]

When you say CO2 (carbon dioxide) do you mean CO (carbon monoxide)?

I assume you mean CO (heavier than air, odourles and colourless gas) as in the gas given off when a fossil fuel (Gas, coal, wood) is burned incorrectly.

C.

[stiggypop]

vulumetric means detecting areas of volume, so normal pir's, dt's etc. Also your pressure wave detector would also i suppose come under this group. You wont find much if anything on them because they dont really work well in most environments. In a sealed draft free box they would.... in a house.... rarely.

Depending on the age of the system will depend on the unit you have. I first saw these about 18 yrs ago made by if i recall MP electronics, little grey and black box. More recently it was bought back to life in the Pyronix Veritec... Neither worked IMHO unless the conditions (ie totally sealed box) were perfect.

Im assuming as you were paying monthly you were either on police response or paid a reduced/subsidised install fee

Depending on the box you have will decide if its any use. ALso its age etc.

All the things the require are readily available, but there are words of caution.

1, no problem

2, no problem but you will find they are seperate detectors. Id probbaly look at wireless for this bit as a smoke sensors needs to be high and central as smoke rises, a co2 sensor doesnt as co2 doesnt rise.

3, can work great but id use sms as a backup signalling path for extra info not your only path. HOw many times have you sent a text that never arrived?

4, no problem

5, Im not a fan of pet tolerant sensors. Some sort of work, others dont really work. If you can limit you pets to an area and use 'perimeter' protection, ie vibration sensors and contacts for doors and windows, maybe glass break detection etc. Then in your other areas use conventional movement detection that will not think a burgler is a dog.

James

Thanks for the info James. This was the company that fitted the alarm but looking at their website they have changed their product to a PIR based system:

http://www.securahomes.co.uk/residential.php

Looks like have been barking down the wrong tree with the word Volumetric - but there are no PIRs. The technology works when there is a change in air pressure I believe as it goes off if the windows or doors or opened in the house too quickly or even if the window has been left open and it has been really windy outside.

To confirm, I meant Carbon Monoxide (CO) - not Carbon Dioxide (CO2) - my fingers were typing too quickly!!

[james.wilson]

Yes thats it pressure wave... IMO still doesnt work lol

But yes CO detectors are the same and need to be mouted at a differint height.

James

[arfur mo]

i've used a couple of these low pressure units, they will work but the problem is setting them up properly and the client understanding they have to close every external window and door - try that 3 months later in summer..

they had to be in the largest room which is often the lounge, so leaving open even a small window on night lock would greatly reduce the effectiveness - as will you cat flap.

i know sales guys were putting these detectors in a fridge then opening a window briskly to demonstrate how effective this type of detection is, a big problem is there is no active testing like anti-masking so should it fail it's likely to go unnoticed for a year on a maintained system, or a lot longer if not maintained.

many modern per resistant detectors can handle pets with no issues and one of the reasons the the pressure sensor faded out imo, but were very handy for those emergency install to give some protection until the proper system could be installed.

regs

alan

[NitroN]

Hi stiggypop,

I am not completely up to date with the DD6662 standard this might make my answer inappropriate :!: . My country has few or no legislative standards for intruder alarms, most EU countries, who mainly only have the EN50131 standards, do not have many of the regulations applied in the UK. (The DD6662:2004 standard is unique to the UK)

PIR's are normally the most cost effective detectors around. Generally "Pet Friendly" PIRs can work well with cats. This depends on where and how they are installed and which type of Pet Friendly PIR is used.

There are some general rules for installation with "Pet Friendly" PIRs . (This will depend on the make and model of the detector)

1. The pet must be below a certain height within a specified distance from the "Pet friendly" detector. Ensure that the detector is not mounted in an area that the cat(s) can come closer to this height/distance.

2. The "Pet friendly" PIR detector should not be tilted.

3. The "Pet friendly" PIR detector should not be looking directly at a staircase or slope.

If you have many cats or a very active cat (always climbing the curtains) then a "glass break detector" can possibly provide a solution, but I have always felt that these are a secondary form of detection.

There are also "Pet friendly" detectors that use multiple technologies that can be effective with premises involving pets. While these sometimes include pressure wave detectors and ultrasonic detectors, I would recommend a "Pet friendly" PIR/Microwave combination. Dual technology detectors are normally more expensive than normal "Pet friendly" PIR detectors.

While I believe in perimeter detection (Magnetic contacts and electronic vibration sensors), I strongly believe that these should be used as early warning detectors backed up by "Volumetric Detectors". (Preferably PIRs or Dual Tech PIR/Microwave detectors.)

Most Alarm Companies would be better able to give you more specific advice after a survey of the premises. I suggest that you get a few to quote, ask them about the type and make of the "Pet friendly" PIR detectors that they use and get them to explain how their specific detectors "Pet friendliness" technology works. Most "Pet friendly" detectors specify weight as a guideline to "Pet immunity/friendliness", but this is just a guideline based on the most amount of IR energy that the average animal of that weight will emit. PIRs cannot judge weight. Some of "Pet friendly" detectors use advanced algorithms to determine whether a signal is an animal or an intruder, while a few others use a more basic technology.

I could go into much more detail, but I feel that this would be inappropriate on a public forum.

Regards

NitroN

[Chorlton]

Great post NitroN

[arfur mo]

some 'pet ressistant' detectors use an algorithyme to filter out animals, rhe idea is an intruder's movements will difer to an animal, so a dog charging the patio door because of a cat the heat source will be fast moving and direct, an intruder wil be making short movements and erratic motions, while the heat source (emmited mainly from the head) is at a lower level for the animal and the intruder is unlikely to travel by making virtical jumps as the dog will make barking at the cat outside.

Cats tend to dart across the room then maybe climb, again different to the movements of even a cat brglar (sorry about that ).

reading the locatingg and set up instructions that come with it before you run the cables is a very wise if boring move, the designers will be the best informed about the chosen detector and how best to use it.

i use rokonet zodiac pets in my home with very good results, and i own a 10 stone 10 year old 'dotty rotty' and no false alarms to date in 6 years.

regs

alan

[NitroN]

Thanks Alan, been looking for a pet immune detector for a customer who has a large dog. I didn't think they made them.

DSC also has a good pet friendly detector, the BV601, which has two dual element pyro's and is rated for pets up to 36 kg.

I have seen this used very effectively with pets, provided you follow the installation instructions.

Regards

NitroN