Motion Sensor Theory of Operation, Remote Activation

[palindrome]

I did a quick search on 'motion sensors' looking for information on what their principal method of operation is. I didn't get any hits so I ask:

I believe they use infrared sensors, not sure what else is available - cheaply and accurately.

My question is what wavelength do the IR sensors respond to (narrow band, wide band) and what power level does the signal need to be, at the detector, for the sensor to detect motion. If the detectors sensor is IR can a matching IR LED be used to remotely activate the sensor, with consideration given to power and atmosphere attenuation? Thanks in advance.

 

[IRstuff]

Most PIR sensors operate in the 8-14 um regime, thereby nullifying any possibility of using any IR LED, unless you plan on dumping lots of power, since the PIR is actually sensing the radiated heat from objects.

In any case, the detector requires motion across its field of regard, since it's the pattern of the time waveform that triggers the alarm.

TTFN

 

[hotspot]

in adition to irstuff's input you might go to

http://www.measure.com/sensors/sensor-roomocc.html

for a little more info.

There is a lot of info on the internet on the subject, but this site kept it short.

Motion detection often includes microwave detection systems. Higher order detection systems commonly use both microwave and PIR in a hybrid system.

Good luck