I had planned to order some IR beams for my Christmas. Now already you might think. But when they need to arrive from Aliexpress, I need to start looking already
But got very recently feedback from a couple of people that they have removed their IR beam devices, due to a lot of false alarms. And although there are probably other kinds of surveillance devices available, I would like to keep the focus of this discussion on IR beams and how I can avoid false alarms.
Some thoughts to get started:
In contradiction to a PIR (passive which means it detects IR from a human body), those IR beams are generated by a transmitter and send to a receiver.
You can buy sets with 1, 2, 3, 4 (and in exceptional cases more than 4) beams. All beams should be interrupted at the same time to result in an alarm. So more beams (with enough distance between the beams) will result in less false alarms I assume?
You can buy devices for different distances (90m, 120m, 250m ...). It seems to me that it is better to buy a long range device, even for shorter distances? Because the beam is not a perfect line, but a rather large cone (with diameter of several meters if I'm not mistaken). I assume that long distance devices have a smaller cone diameter, so less false alerts?
If there is fog or the cover of the transmitter/receiver are dirty, then the beam will be diffused. As a result a weak IR beam will arrive at the receiver, so this might become a false alert.
Some devices have build-in amplifiers and DSP processing to solve some of these problems, but it is hard to see which devices are better than others ...
Here is an example of such a 3-beam device set:
Any thoughts or experiences?