External detection is increasingly in demand from end users seeking to achieve an early warning of intrusion. In the past external devices were often used solely to switch lighting or to trigger other devices due to issues with police response. However, as the opportunity for advanced integrations grows and smart systems become more popular, external detection not only enhances security but also adds real value for end users.
When it comes to intruder alarm detection systems, external detection is often underused by installers and integrators. Many feel that passive detection devices – usually PIRs or PIR and microwave combinations – are vulnerable to nuisance activations in external environments.
The general perception that outdoor detection devices are susceptible to false alarms is somewhat outdated. Credible manufacturers have enhanced product design over the years, and external detectors can often be more stable than average internal sensors!
Nuisance alarms can happen in an external environment, and when designing a system this has to be considered. However, missing a genuine event is more critical, because the point of external detection is to identify intruders, before they have an opportunity to cause loss or damage.
Texecom: Premier External TD-W
The Premier External TD-W is a wireless outdoor PIR sensor. It can be used for monitoring open areas and reporting intrusions, or for switching additional systems such as video surveillance, lighting, etc..
The detector makes use of two separate non-overlapping PIR sensors; both must detect motion for an alert to be generated. The first sensor has a detection field which is at 90 degrees from the unit, thus providing a flat plane of detection at the mounting height (this is 1.0–1.4 metres). The second detection zone is angled downwards and can be adjusted to allow range limitation if required. This makes it flexible for most applications.
The sensor offers a volumetric 90 degree coverage with a range of up to 12 metres. As mentioned, this can be limited to 8, 5 or 2 metres using a simple rotary adjuster. The detection heads can also be rotated through 180 degrees; this eliminates issues with device mounting and adds to the overall flexibility.
To ensure accurate performance, the sensors make use of mirror optics. Mirror-based devices are often preferable to devices using fresnel lenses as the focus of infrared activity is more precise.
The detector makes use of Texecom’s Ricochet mesh-based wireless platform. This allows the creation of a robust and reliable wireless network which is self-healing, ensuring that communication with the control panel is ensured even if environmental conditions impact on a direct link between the device and panel. The External TD is also available as a traditional hard-wired device.
One feature of the Premier External TD-W is that the device includes a light sensor. This allows a day/night mode to be used for configuration. In day/night mode the sensor is active around-the-clock, while in night mode it is only active during the hours of darkness.
The TD-W measures 89 x 86.5 x 250mm, is rated to IP65 and is available in black or white finishes.
It is powered by two 1.5V AA lithium batteries which are included with the sensors. A battery life of up to four years is quoted. The detector is EN50131-5-3 Grade 2 Class IV.
The Premier External TD-Ws on test have been installed for six months as a part of the long term Benchmark Smart Solutions project and have been deployed continually during periods of extreme heat, snow, ice, rain and gales. During that time the only nuisance activations were created by intentional attempts to see how far the performance could be pushed. In normal operation there has not been a single false alarm, nor have incidents been missed. There have also been no problems with performance or operation.
The detectors are particularly suited to use with the Texecom Connect smart system. They have performed well in scenarios ranging from double-knock intruder detection through the automation of gates and lighting, to forming part of lifestyle applications used during social events.
Installation is simple and configuring the devices is also very straightforward. Setting include pulse count (2, 3 or 4), sensitivity (high, medium or low) and day/night (day/night or night only). Range and angle adjustment uses a dedicated rotary controller.
The TD-W combines flexibility with a high degree of stability and accurate detection.
GJD Security: D-Tect3
The D-Tect3 from GJD Security is an external detector with a range of 30 x 30 metres. Designed predominantly for use in applications where switching is required for other systems, it can be deployed for a wide range of detection needs. The product is well established and is proven in the field. It is hard-wired, but GJD do offer similar detectors for IP connections or wireless systems, including one slightly higher spec model that is compatible with the Ricochet wireless mesh-based platform.
The detector makes use of both PIR and 10.587GHz microwave technologies. Maximum range is 30 metres, but this can be adjusted to 25, 20, 15 or 8 metres via a straightforward process.
Maximum angle of coverage is 70 degrees, although this can be reduced in 10 degree increments down to a minimum of 10 degrees. This is achieved by the use of sliding ‘curtains’ which are used to mask off the edges of the sensor. The detector also includes additional ‘curtains’ which can supplement the fitted ones should very tight angles of coverage be required. This, along with more traditional masking, ensures that the detector’s field of view can easily be customised.
Mounting height is 3 metres, but this can be increased to 6 metres if required. However, this will impact on performance with regard to range and the time taken to accurately detect targets.
Mounting flexibility also includes the ability to tilt the detector through 45 degrees and pan through 90 degrees. Replacement tamper switches also allow for uneven mounting surfaces, showing that the manufacturer has taken the issue of external mounting seriously.
The sensor features two volt-free and two negative switching outputs. Installation is simplified through integral EOL resistors; these are set via two banks of jumpers.
The opaque cover of the detector is retained using a screw, and once removed the connections, jumpers and configuration button (more about this in a moment) are revealed. Alignment of the detection head is simple and clear marking assists with this. The various connections and jumper settings are obvious and easy to follow.
For installers and integrators who are new to the DTect range, the method by which the main configurations are set are different to many other detectors. It can be a little perplexing the first time it is encountered, but it is straightforward and does allow a good degree of flexibility.
There is a single configuration button which controls all settings aside from the EOL choice. Each setting has a number: 1 for Range, 2 for Pulse Count, 3 for Pulse Count, 4 for S Output Lux Level, 5 for Contacts, 6 for Timer, 7 and 8 for auxiliary functions.
The configuration button is then pressed the appropriate number of times to activate the menu. For example, to set range it is pressed once, to set pulse count twice, etc.. It will then display an LED to show it is the appropriate mode and ‘flash out’ the current setting.
Each option has a value; for Range, 1 is for 8m, 2 for 15m, 3 for 20m, 4 for 25m and 5 for 30m. If you wanted to change the range you push the button once (to select Range), and it will then flash to identify the current setting (4 times, for example, if it is set to 25m). If you wanted to change the setting to 15m, you then press the button twice.
Based upon experience, we would always recommend that installers and integrators write down the settings they want to change, along with the associated numbers, before starting the process.
The flexibility with regard to positioning works well and allows simple alignment. In the field, the detector is stable and consistent with regard to performance. Nuisance activations only occurred when we tried all the things that common sense tells you not to do! In normal operation there were no issues whatsoever and all genuine intrusions were detected quickly and consistently.
The only part of the installation process that does take a little time is the button-based configuration. Make notes beforehand and it will be quicker and easier.
Takex: PIR-T15WE
The PIR-T15WE from Takex is an external PIR detector designed for outdoor use. Range is 15 metres, and the coverage pattern is 80 degrees; this slightly increases dependent upon the selected operational mode. To aid with flexibility, the sensor is capable of supporting four modes: Low Position, High Position, Pet Mode and High Density.
The first two modes are self-explanatory. The first allows for a mounting height of 2.0–2.7 metres and the second a height of 2.7–3.5 metres. Pet mode allows for discriminations that filter out typical pet activity, while the High Density mode allows mounting at heights of 2.0–6.0 metres. The latter is used for enhanced detection but does work best in a more stable environment.
The sensor utilises a triple mirror-based PIR set-up. Features include detection area adjustment and a dual output to allow triggering of secondary devices. The housing is specified as IP55.
Precise alignment is achieved through a well-designed mounting arrangement, showing that this is not simply a standard PIR with a few adjustments for external use. Removal is straightforward when you need to gain access to connections and DIP switches.
There are two banks of DIP switches. The first manages LED operation, alarm memory, sensitivity (40, 70, 100 and 130 per cent), environmental adjustment, operational mode and creep zone (not active when in Pet Mode).
The second bank of switches are used to configure walk test, LED memory, contact status, secondary output, near area disable and long-term diagnosis. Setting the configurations is very straightforward.
In terms of both stability and catch performance, the PIR-T15WE does what is needed. We saw no nuisance activations in normal use, aside from deliberate attempts to push the performance beyond the limit!
Catch performance was very good with all genuine intrusions being detected quickly and with accuracy. It also managed some fairly testing environmental conditions without any issues.
BENCHMARK VERDICT
Texecom: Premier External TD-W
It must be said that the Premier External TD-W from Texecom has had the hardest workout in this test, because it has also been used in a long term test that has pushed its capabilities as a security detector and a trigger device for integrated solutions and automation applications too.
The detector has not missed a genuine intrusion, nor have their been any issues relating to everyday performance. Easy to install, reliable and accurate, in terms of performance it achieves Outstanding status. Whether installers and integrators opt for the wireless model or the hard-wired version, they will not be disappointed, and in this test it is also rated as the Best Buy!
GJD Security: D-Tect3
The D-Tect3 from GJD Security is a well established detector and for good reason. It has been well designed, it offers consistent performance and includes a number of features that deliver flexibility in the field.
For most installers and integrators, the detector will be specified in applications where switching is required, although that shouldn’t be seen as a limitation because triggering is increasingly required for smart systems. The configuration does take some getting used to. However, in terms of performance, it achieves Recommended status.
Takex: PIR-T15WE
The PIR-T15WE from Takex is arguably the device most reminiscent of a traditional external detector that was involved in this test. That said, it should not be considered as an average external device. The design has considered the typical challenges faced by an external unit and addressed them. Its true strength lies in accurate and consistent detection, but it is just as capable of being deployed for switching tasks.
Using triple mirror optic-based sensors ensures that catch performance is very good, and with regards to installation the process is simple, as is set-up.
Throughout the duration of the test the detector behaved very well, even during challenging environmental conditions. As such, it achieves Recommended status.
