Honeywell DT7435

DUAL TEC Motion Detector

Honeywell dt7435 dual tec motion detector
  • Honeywell dt7435 dual tec motion detector
  • Honeywell dt7435 pet alley diagram
  • Honeywell dt7435 long range curtain diagram
  • Honeywell dt7435 mounting diagram
  • Honeywell dt7435 detection diagram

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The Honeywell DT7435 is a DUAL TEC® motion detector that combines passive infrared (PIR) and microwave technology to provide the best det...

This product has been discontinued and is no longer in stock.


The Honeywell DT7435 is a DUAL TEC® motion detector that combines passive infrared (PIR) and microwave technology to provide the best detection possible. Honeywell was the first security manufacturer to combine both technologies in a single motion detector and they trademarked the name DUAL TEC (DT). However, just like with all great technological innovations, nearly every security manufacturer quickly saw the advantage of a dual technology motion detector and therefore there are many imitations of the DT Series motion detectors available today. By combining the PIR technology with microwave detection, DUAL TEC motion detectors are much less likely to trigger a false alarm.

The DT7435 can detect motion by sensing a change in the ambient temperature of a room using the PIR technology and can also detect movement by transmitting energy out into the room and sensing a change in the frequency of the energy received back at the device using the microwave technology. PIR motion detectors are prone to false alarms when there are lights or heaters in the room that may rapidly change temperature. Microwave motion detectors are prone to false alarms because the microwave energy can “see” through walls and therefore trigger an alarm when there is movement outside of the protected area. As PIR and microwave motion detectors are both susceptible to false alarms for different reasons, a DUAL TEC motion detector that requires both technologies to go off together is the best way to reduce false alarms.

The Honeywell DT7435 is an advanced DUAL TEC motion detector that utilizes Honeywell’s DualCore™ signal processing which analyzes both the PIR and microwave signals through a single microcontroller. The DualCore signal processing has concurrent diagnostics, digital fluorescent light interference filter, digital adaptive microwave threshold, adaptive baselines and bi-directional temperature compensation to provide the most accurate detection possible. Also, the microwave technology operates with K-Band technology which provides a broad, balloon-shaped pattern to match the PIR detection area. The K-Band microwave technology also features pattern containment to ensure the microwave energy does not penetrate walls. Finally, the custom PIR Fresnel lens features uniform sensitivity optics which provide the same sensitivity for detection at the edge of the detection pattern that is found in the middle of the detection pattern. Motion detectors that lack uniform sensitivity optics do not provide consistent detection throughout the covered area.

The DT7435 DUAL TEC motion detector was designed to be mounted on a wall 7’6” from the floor. We recommend this mounting height, if at all possible, so that the detection pattern works as designed. The range of the DUAL TEC motion detector when mounted at this height is 35’ from the motion detector and 40’ wide at the end of the cone shaped detection pattern. The PIR detection pattern consists of (4) look-down, (6) short range, (12) intermediate and (22) long range fields of view. The PIR detection pattern along with the DualCore signal processing, uniform sensitivity optics and K-Band microwave technology provide pet immunity up to 100 lbs. without sacrificing detection reliability when there is a real intruder.

Brand: Honeywell

Good Dual-Tech Motion Sensor
Submitted on 08/23/2019 Alarm Grid


The Honeywell DT7435 is a fine dual-tech motion sensor. But it has since been discontinued in favor of newer and more advanced models. If you need a hardwired Dual Tec motion sensor, then there are better options to choose from.

As a dual-tech motion detecting sensor, the Honeywell DT7435 uses both microwave detection and passive infrared (PIR) detection when looking for movement. The sensor will only alert the system if both its microwave sensor and its PIR sensor are activated. This is great for preventing false alarms for environmental conditions that may activate a motion using a PIR-only sensor. These include air from heating vents, sunshine through windows onto objects in the room, and so on. By using a microwave sensor and PIR sensor together, you get a much more accurate motion detector.

While the DT7435 works fine as a dual-tech motion sensor, there are now better options available. That is why Honeywell decided to discontinue this model. If you are in the market for a new Honeywell Dual Tec Motion Sensor, then there are better options to choose from. These include the Honeywell DT7450, the Honeywell DT7450C, the Honeywell DT8035, and the Honeywell DT8050. These motion sensors all offer a superior coverage area over the DT7435, which only spans an area of 40 feet by 35 feet.

Although the pet immunity for animals weighing up to 100 pounds is an excellent feature of the Honeywell DT7435, that same pet immunity feature is matched by the Honeywell DT8035. Our technicians have found that pet immunity works just as well on both of these devices. So if pet immunity is of major importance for you, then you can just go with the DT8035 instead of the DT7435.

Bottom line, we cannot recommend the Honeywell DT7435. There are better hardwired dual-tech motions available.

I will try and read the manual again and understand it but I tried reading it over and over again.
This is a Dual Tec motion meaning that both the PIR and microwave sensors both need to trigger to actually set off an alarm. If you see the yellow LED but not the green LED, the sensor won't trigger the red LED and sound an alarm because only the microwave technology is being activated. I suggest you read through the installation guide I emailed you again as all of this is described in detail.
Thank you and problem solved. I installed the pir to face the glass window and glass door,the sensitivity is set to high and the zone finder is set to 75%. When I walk pass the glass window and glass door,the microwave movement on the pir(led) turns yellow but it doesn't trigger on the panel,it remains normal. Why doesn't it trigger to the panel when led turns yellow or how does it work?
The tamper protects the motion if the cover is removed. It will send a tamper alarm on the zone wired up for the tamper in the motion when the cover is removed. If you are getting tamper alarms when the cover is not removed, you probably have a wiring issue. You can also just disable the tamper zone as it's not needed for the motion to work.
Hi thank you again. I want to ask you something about this passive because I haven't worked it with and thats why am asking you this questions. I went and replaced a pir with new one,whereby control room was saying the pir was sending false tamper signals,because its far,i did the trouble shooting on the pir and replaced it with a new one,a week later control room logged a call saying the very same pir is sending tamper false signals again,the pir is connected on a risco panel,the connections on the pir are as following: 2k2 resistor across the tamper and another 2k2 across the alarm(NC and com). The is a loop btwn the trouble and the tamper terminal on the pir. The zone wires are connected from the trouble terminal and the NC terminal Then you have 12v power running to your pir. Thats how the connection is being made and I made sure that the tamper switch on the pir makes good contact with the metal plate cover of the cover plate of the pir,and it was clicking when I closed the cover. So my problem is that I don't know what makes it to send tamper signals and it doesn't send it immediately and that makes it very strange to me cause when I leave site every thing is in order cause when you trigger pir it goes open(alarm) and when it resets it goes close( normal) The trouble on the pir what is it used for? I have been working with alarm and tamper most of the time,i don't know what the trouble is used for. Thank you and will hear feed back from you.
That is part of the motion sending electronics.
The is a mirror inside the pir wrapped with black rubber arround it,what work does it perform that mirror?
It's discontinued so I'm not sure on cost. You'd probably have to search eBay or Amazon to find a seller.
Thank you,i got the attachment,i will install and test and come back to you,my main concern was to test it on solid walls and window and see if it activates via microwave. How much can this passives costs?
I just emailed you the requested document. Also, keep in mind that a Dual Tec motion needs to have both technologies activated (PIR and microwave) so if the microwave sensor detector motion but the PIR sensor did not, you would not have an actual alarm event.
Thank you,don't you perhaps have the instruction manual with you,than you send it to me please via email, I would like to wire and test before. Thanks
The Dual Tec motion can sense motion via the microwave input through walls and solid objects, if the microwave intensity is set too high. This is one of the reasons you walk test it by setting the Microwave to the lowest setting, walk testing, then gradually raising the Microwave strength until it picks you up where it should, without tripping the Microwave when it shouldn't.
Can this passive DT 7435 sense motion via microwave from the other side of the wall or glass door?
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