We have a fair few different types of PIR sensor on our site, the following are commonly used in burglar alarms.
This is the standard passive infra red sensor that simply picks up infra red wavelength body heat. The sensor emits not energy or beams, hense the name passive infrared.
DT / Dual Tech
Dual-tech sensors have both an infrared sensor and a microwave sensor in one unit. For the sensor to be triggered, both sensors must trip together. This lowers the probability of a false alarm since heat and light changes might trip the infrared sensor but not the microwave, or moving tree branches may trigger the microwave sensor but not the infra red. Brilliant for harsh environments like garages, sheds, outhouses where bugs, creatures or debris may trigger a standard pir.
TD / Twin Dual
Much like the a standard PIR but features twin infrared elements, for greater sensitivity.
QD / Quad
Quad element sensors are much like standard sensors but have the infrared beam split into 4 hot and cold zones in the form of a square. The onboard chip then decides whether it is a true alarm depending on the pattern 'seen' in all 4 of the zones. This can significantly reduce the number of false alarms. They offer a greater reliability than standard PIR's and are often purchased instead.
PW / Pet Immune / Petwise
Have a decreased detection threshold at the beams lowest angle, so they are less likely to trigger with movement closer to the floor, e.g dogs, cats. Some of the PIR's available have a selectable weight and can even be turned off completely to function as regular PIR's. Positioning is key with these PIR's as climbing animals (like cats) could still trigger the device.
These are typically ceiling mounted and have a full 360 view and offer great all-round coverage. They can also be available as Dual Tech, Quad or Pet Immune.
Texecom amongst other manufacturers, do a range of PIR's with an interchangable printed circuit board inside the casing. This enables you to swap different types of PIR around the premises without having to remove the actual unit off the wall.
Wireless and Ricochet Wireless PIR's
The technology in wireless sensors has improved massively even in the past 10 years alone. Thanks in part to advances in battery technology, wireless PIR's are now a reliable, often requested accessory for alarm systems. Mostly powered by lithium battery that guarantees 2> years of battery lfie with standard use. Wireless PIR's allow you to expand on an existing wired security system or secure an entire property without the need for adding cables. This is great for recently decorated properties or locations where cabling could potentially be a nightmare.
Texecom have a range of wireless PIR's that utilize the popular Ricochet wireless technology. This technology boosts the signal of a wireless alarm by utilising the PIR (and other devices) to boost the range of the wireless signal carried across it (Abit like a WiFi extender). With this, a property secured with a handful of PIR's and contacts, creates a web that boosts the signal across it, as well as giving full security coverage.
Some brands such as Texecom and GJD produce outdoors PIR's specifically designed for alarm systems. With non-overlapping infrared sensors and mirrored optics that create an outstanding level of false alarm immunity to triggers from the sun, reflections and shadows. These sensors are usually IP65 rated and in the case of some GJD sensors, can have additional microwave sensors giving an even higher level of false alarm immunity.
Lighting PIRs and presense detectors can work a little differently to a regular alarm PIR. They can have LUX sensors (also known as built in light level sensors) that will stop the light from activating if the ambient light level is already high. They can have manual overrides and adjustable lighting levels.
Brackets and Wall Mounting
Nearly all sensors sold can be surface mounted. This will involve removing the cover and drilling through the screwholes through the back of the case. Some come with screws and nearly all PIR's have an optional adjustable bracket that can be fitted. The Texecom PIR's have adjustable brackets that are sold seperately. Each starting with the product code AFU-000. As is usually the case, most brackets are designed to be fixed to a wall then allow the PIR to simply clip onto it.