Honeywell DT7435 Posts

Hi DIYers! You may have heard the term "Dual Tec Motion Sensor" being tossed around at some point or another. The term refers to motion detecting sensors that use two forms of detection for picking up movement. Usually, these two methods are passive infrared sensing and microwave detection.

A common complaint with motion sensors is that they are known to cause false alarms when mounted improperly. This is usually caused by having the motion sensor placed near a window, a ceiling fan or an air vent. The motions that cause these false alarms are usually PIR-exclusive sensors that use only one method for detecting motion. Now, these sensors will generally work very well and won't cause any false alarms when mounted properly.

The reality is that most false alarms caused by motion sensors are the result of poor mounting. But having a second detection method for verification can go a long way towards preventing any system false alarms. Although proper mounting is still very important, you might be able to save yourself some major inconvenience by springing for a more-advanced motion detection sensor. This is where Dual Tec Motions can come into play.

Honeywell Dual Tec Motion Sensors use passive infrared (PIR) detection and microwave detection when looking for movement. In order for one of these devices to activate and alert the alarm control panel, both the PIR sensor and the microwave sensor must activate. Nothing will happen if only one part of the sensors is triggered. This can be very useful if a single technology sensor is prone to randomly activating due to local environmental sources. The name "Dual Tec" comes from the fact that the sensors use two technologies in detecting motion.

The PIR sensor in a Dual Tec Motion will work by looking for changes in infrared (IR) energy that occur with movement. Every person, animal and object gives off some amount of IR energy. If a large mass of IR energy from a person or large object moves within the field of view of the PIR sensor, then it will signal that motion is present. Meanwhile, the microwave sensor will send out continuous signals that are designed to bounce off of objects and return to the sensor at a consistent rate. If the signal pattern changes, then the sensor will assume that motion is present.

Although a PIR sensor can technically work by itself, a microwave motion sensor would cause too many false alarms on its own. This is because microwave signals can pass through objects and walls, and they could very easily detect movement that occurs outside the building. But the PIR sensor will not work through walls, so it will only detect motion that occurs from the inside.

However, pairing a PIR sensor with a microwave sensor in a Dual Tec Motion Sensor results in the perfect team. Even if the PIR sensor responds to flowing air or sunlight or some other local change in IR energy, the microwave sensor will keep it in check. Likewise, the PIR sensor will not respond to the outside movement that may trigger the microwave sensor. But both sensors will still respond very reliably to any real motion that is actually present in the building. And once that happens, it's game over for any intruders!

Honeywell offers Dual Tec Motion Sensors of all types. Their Dual Tec lineup includes wireless motion sensors like the Honeywell 5898, as well as wired motion sensors like the Honeywell DT8035. There's even a long range Dual Tec Motion, the Honeywell DT906, that is perfect for large commercial settings that require the highest level of protection possible. Honeywell has truly covered all their bases here!

You can get all of these great Honeywell Dual Tec Motion Detecting Sensors from the Alarm Grid website. If you need help deciding on a perfect motion detector, please reach out to us by emailing support@alarmgrid.com, or by calling us at (888) 818-7728 during our normal business hours of 9am to 8pm EST M-F. We look forward to hearing from you!

While we currently offer wired motion detectors that utilize passive infrared (PIR) technology, the DT7435 is the first Honeywell DUAL TEC® motion detector offered by Alarm Grid. Motion detectors that use PIR technology are the most common type of motion detector. PIR motion detectors are able to detect the ambient temperature within a protected room. If an intruder enters the room, the PIR motion detector senses that their body temperature is different than the normal environment and an alarm is triggered. However, motion detectors that rely on PIR technology only can be susceptible to false alarms. Therefore, Honeywell DUAL TEC motion detectors are valuable because they introduce microwave technology which is used in conjunction with PIR technology.

Motion detectors that use microwave technology emit microwave energy and detect the frequency of the energy reflected back to the motion detector. If an intruder enters the protected area, the frequency changes and the motion detector triggers an alarm. Unfortunately, microwaves go through walls and therefore motion detectors using microwave technology only would not be useful as they would detect movement outside of the protected are and cause false alarms.

Honeywell DUAL TEC motion detectors like the DT7435 combine both types of detection to make a motion detector that is extremely unlikely to trigger a false alarm. If you have experienced false alarm issues with your current wired motion detectors, you should consider swapping them out to the DT7435 DUAL TEC motion detector.