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Alarm sensors that can pass through walls.


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As a title, what are the technologies of alarm sensors that can detect movement through walls?

From what I know are only those who use microwave technology up to 10 Ghz.

Any indication in this regard is welcome.

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Microwave are the only detectors available that will see through solid objects, they use radar dopler which travels through solid objects and detects changes, such as moving objects. Whereas ultrasonic use sound a bit like how a Bat hears, there is a tx and an rx they tx a ultrasonic noise which bounces around the room and at the same time the rx listens to that noise. If anything in the room moves the sound it receives changes. Infra red see's heat movement.

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Microwaves will both penetrate and reflect back from surfaces, the reflected signals are processed to detect changes. Ultrasound will penetrate thin surfaces (for example a sonograph) but most if not all would be absorbed or reflected by surfaces when used in a detector.Ultrasonic went out of favour and replaced with other technologies like IR and MW due to health concerns.

Any detection method that could penetrate outside of the protected area would normally be in a combination detector now (a DT or Dual-Tech), the other technology being passive infrared as the idea is to detect movement only within the area you are protecting. Installers would adjust and test the MW range on detectors they fit to avoid false alarms.

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18 hours ago, al-yeti said:

Thermal imaging would do it 

 

I have a Flir E6 - EX and unfortunately thermal cameras can't see through walls. TI can see differences in the temperatures in buildings and structures. So you can see wall studs, window frames, a/c ducts, etc. These cameras only “see” heat as it radiates off of an object. It may “see” the heat coming from a house, but it can’t see into the house because the camera picks up the house’s exterior thermal image first. In fact, the thermal imaging doesn’t even see through glass because the glass has its own thermal profile.

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10 hours ago, glf said:

Is it physically possible that the microwaves crossing the wall generate a false alarm for only half of the room crossed, not causing problems in the other half ?

Can you say that in English?

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12 hours ago, PeterJames said:

Can you say that in English?

 

Yes Teacher ! Sorry if my english is not good, but I just arrived from Africa on a boat and I did not have time to study...

Feel free to correct the wrong sentences using your red pen, teacher …

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9 hours ago, glf said:

 

Yes Teacher ! Sorry if my english is not good, but I just arrived from Africa on a boat and I did not have time to study...

 

Feel free to correct the wrong sentences using your red pen, teacher …

 

Yes we came to this country , to learn how to be real alarm men , but they talk to us as if we don't know how to twist leaves together and make the circuit,  maybe I find forum in Wales they have different rules there ....

 

(Please read in African accent )

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14 minutes ago, al-yeti said:

Yes we came to this country , to learn how to be real alarm men , but they talk to us as if we don't know how to twist leaves together and make the circuit,  maybe I find forum in Wales they have different rules there ....

 

(Please read in African accent )

 

All these yrs I've read all your content like Apu from the kwik-e mart

 

 

Mr😀 Veritas God

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40 minutes ago, MrHappy said:

 

All these yrs I've read all your content like Apu from the kwik-e mart

 

 

Ah ok doh!

 

Far from it tho lol 

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2 hours ago, MrHappy said:

 

All these yrs I've read all your content like Apu from the kwik-e mart

 

 

His accent is more "innit geezer !!!"

12 hours ago, glf said:

 

Yes Teacher ! Sorry if my english is not good, but I just arrived from Africa on a boat and I did not have time to study...

 

Feel free to correct the wrong sentences using your red pen, teacher …

 

Well if you want to be understood you need to make fookin sense!

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