An infrared detector is still a very good device and will be a very effective tool, as long as it is used strategically and all installation and calibration processes are done correctly. A PIR, or Passive Infrared, detector is limited only to receiving infrared light. The device cannot emit infrared light, like other types of infrared motion detectors can. A PIR sensor also cannot sense a fixed or stationary object. It cannot detect a very slow moving object as well.

Since a PIR sensor is sensitive to temperature, this device works best at ambient air temperature. Ideal temperatures for these devices to work are between fifteen to twenty degrees Celsius. If the air temperature is above thirty degrees, there is a possibility that the PIR sensor will become less sensitive to movement. If the air temperature is lower that fifteen degrees, the sensor's scope widens and the device will be activated by smaller objects, or those that are very far from the device.

Another limitation of an infrared detector is that it cannot "see" through windows, walls, or doors. The rays that the detector emits are not capable of bending around corners. Thus, this device should be strategically placed, particularly in areas that are more vulnerable to intrusion, or areas that are highly likely to be used by intruders to enter the house or room.

Although the infrared detectors have some faults and admittedly have some limitations, this does not mean these devices do not deserve to be recommended or are no good to use. No gadget or device is perfect, as there will always be people who will be able to find faults with it, regardless of the device.

As for PIR cameras, we do have a few that are highly recommended as following:

(SKU: PL1179) HD 600TVL 1/3" Sony Super HAD CCD 10m IR Pin-Hole Indoor Camera PIR

Features:

1. PIR pin-hole cameras.
2. 1/3 Sony color Super HAD CCD
3. (DSP) allows better picture quality and full function control
4. High Resolution 600 TVL lines
5. Low sensitivity Lux(Infrared LED on )
6. Built-in 18 leds
7. 850nm OR 940nm(invisible IR light): 850nm is default
8. Pin-hole 3.7mm lens

(SKU: PL0205) 1/3" Sony CCD Chipset IR Pin-Hole Camera PIR 18 Leds 520TVL

Features:

• PIR pin-hole cameras.
• 1/3 Sony color SuperHAD CCD
• Sony SS11& SS11X&HQ1 Digtial Signal Processor
• (DSP) allows better picture quality and full function control
• High Resolution 520 TVL lines
• Low sensitivity Lux(Infrared LED on )
• Built-in 18 leds
• 850nm OR 940nm(invisible IR light): 850nm is default
• Pin-hole 3.7mm lens