Prone to false alarms from leaves or birds etc interrupting the beam

The transmitter emits a beam of infrared (IR) light and the receiver picks up this beam. When the beam is interrupted, the receiver alerts its alarm control panel by opening a relay. Most beams used in security applications use multiple IR beams in order to reduce false alarms and to increase the area covered.
_

Alta:
Last week this guy and I would talk a ton in class and he would smile at me a lot etc and then over the weekend I snapchatted him saying something and then after that we were sending back and forth selfies.
(8 September 2016)

Elda:
Just cause 3?
(8 September 2016)

Austin:
My boyfriend stole my shoes and socks?
(8 September 2016)

Regan:
I caught him looking at me everytime when i walk down the road?
(8 September 2016)

Esmeralda:
Who was in the wrong in this situation?
(8 September 2016)

Esmeralda:
Am I in the wrong for wanting compensated for the value of original item?
(8 September 2016)

Esmeralda:
Now both A and B are mad at me because I should have dropped it and let it go after B took her item back.
(8 September 2016)

Esmeralda:
So I ask A if I can have another of her items to equal out the value of the original item I gave her.
(8 September 2016)

Esmeralda:
Weeks later B asks for her item back.
(8 September 2016)

Esmeralda:
So I gave A my item and she gave me her lesser valued item as well as B gave me hers.
(8 September 2016)