bababouy
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This device may just make cameras and our service more valuable than it already is. We will have the ability to see this device being used in real time. This device isn't driving the car away by itself?
door checkers caught
- Thread starter bababouy
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bababouy
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That is the beauty of a PIR, trees and shadows should not trip the device. It is tripped based on a change in temperature along with motion. Believe it or not, if you mount the optex devices at 6' - 6'5", you will increase the sensitivity and range. The directions say to mount no higher than 8', but often times we don't take into consideration the amount of downgrade in in the earth from where the device is installed on the building. This measurement should be taken when you are standing where you would expect an intruder to trip the sensor.
Kawboy12R
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That's what I said. Invaluable is the opposite of not valuable.
Invaluable - beyond calculable or appraisable value; of inestimable worth; priceless
bababouy
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The headlights will not trigger these. If the vehicle gets with in range, the heat coming from the engine bay or the exhaust will trigger them.
To clarify- the PIR sensors trigger on changes in heat. If the sensor is pointing only at the garage, it won't see the headlights shining on the garage, because the garage hasn't been heated up by them. But if the sensor has a view of the road it will see the headlights, because the headlight bulbs themselves are hot.
If you've got big leafy plants around, they can be triggered by wind. For example, if you get wind just after sunset and the day was hot, the ground will still be warm but the plants have already cooled off. If the wind blows the plant leaves around, the sensor will see the cool leaf moving and uncovering the warm pavement or earth behind it, and it can trigger on that. I try to keep any plants that will move in the wind out of the sensor's field of view. That's more easy with the LX-802n because the beam is really narrow.
If you've got big leafy plants around, they can be triggered by wind. For example, if you get wind just after sunset and the day was hot, the ground will still be warm but the plants have already cooled off. If the wind blows the plant leaves around, the sensor will see the cool leaf moving and uncovering the warm pavement or earth behind it, and it can trigger on that. I try to keep any plants that will move in the wind out of the sensor's field of view. That's more easy with the LX-802n because the beam is really narrow.
bababouy
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You are correct on all of this. If a vehicle gets close enough to a PIR to where the heat of the bulb is going to be sensed, the sensor will already be picking up the heat from the vehicle, engine, brakes, tires etc..
PIRs are definitely a bit more of a challenge during the day and in particular, sunset and sunrise. Your description is spot on with the plants being cooler than the ground or surrounding air. These PIRs definitely work their best at night or away from big leafy plants.