How Modern Motion Detectors Prevent False Alarms
So mirror motions have better false alarm protection. They have the bug guard, which is this. This is sort of its own bug guard because of the way the mirror is made. They also have what they call white light immunity, just like when you go to the eye doctor and they shine that bright light in your eye, and then for a little while after that you can't see very well? Motions are the same way. If you shine a bright light in the front of the motion it has difficulty being able to see anything. The reason these bug guards are black is because this helps to absorb some of the white light that you might have in an environment. So white light immunity. That's a speck. I don't really know what 6500 lux means. I know it's a rating of light, but I don't know what it means as far as this motion is concerned. They also have better processing power now. So they have just better chips in them that allow them to do better analytics than what they used to be able to do. So we talked about-- Jonah talked about one time they a thing on Mythbusters where if you go into a place where you know there's a motion and you move slowly enough, you can defeat the motion. And that's true, but you have to move really, really slowly because basically, as you move very slowly, you trip an area, and then if you stand for a long time, the motion is going to kind of forget that you tripped that area because you didn't trip another area within a certain period of time. I don't what that period of time is. So technically, if you move very, very slowly, it is possible to defeat one of these. There's also masking, and we'll talk about anti-mask features. I found out in Europe, probably 15 years ago, maybe, that on a motion like this, you can spray it with hairspray and then it's blind. It can't see anything. You can spray it with other things, too, like adhesive, paint, whatever, but hairspray is clear. So you could go into a business, stake it out, see what's what, see where all the motions are, take a little can of hairspray with you, spray that while they're open, and then come back later and run around with impunity. So they started making these with better processors with anti-mask features, where if somebody does attempt to do that, the motion will trigger trouble. So dual-tech motions use both microwave and passive infrared detection. Dual-techs are used when there's an environmental factor that will cause a PIR to trip because the environmental factors that will trip a PIR won't trip a microwave. So for example, we were talking about the sun coming in the window and hitting a certain area on the wall and heating it up quickly enough to fool a motion into thinking that there's somebody there. That environmental factor would never trip a microwave. The thing with microwaves, and why you'll never see a microwave only motion detector is that they can see through walls. You have to-- they're hard to adjust. There's a potentiometer, usually. In fact this one has a potentiometer right there. So you have to really thoroughly walk test them, you have to make sure that it's not see through the wall, because if this is turned up too high and it sees motion in another room, where it's not supposed to see, or outside the building, and that environmental thing happens that causes the PIR to trip, then it can go off. But usually that's the only time you're going to use a dual-tech, is when there's some kind of weird environmental feature that causes your motion to trip and give you a lot of false alarms. One thing that I think a lot of people don't take into consideration is environmental things like that, it can happen, maybe over a course of two days, and then may not happen again for a year, because the earth is always turning, it's tilting, so somebody calls in and says, why did my motion go off, well it could just be that day.