What our experts say …
“Just what the world needs – another PIR.”
Installers might be forgiven for thinking that, since a glance through the product catalogue of one UK security equipment distributor alone reveals in excess of 70 different models currently available. So how do manufacturers get an edge on their competition nowadays? Read on …
Cooper Security has released the ‘4’ series of movement detectors, under the Scantronic brand. It includes ceiling mount, quad and digital PIRs, plus two twintec types. The 420 on test is a simple domestic PIR with intelligent software to achieve greater detection accuracy and a high level of performance stability. The unit comes with a generous six-year guarantee.
The two-part case is constructed from a very rigid ABS plastic in a white finish, with a neat white-headed screw on the underside to secure the cover. The whole package is very rigid and gives good protection from casual vandalism, including the fresnel lens which takes the form of the increasingly popular spherical shape. If the PIR is sited in a vulnerable position it is possible to push the lens out of shape, but this requires some force and that of course is true for any detector with a fresnel lens. The shape is a very modern, globular design that we found attractive. The entire case is sealed against insect and dust intrusion, including the optical chamber, so the cable entry and wall mounting holes need to be created in the usual knock-out positions for either flat wall or corner mounting.
Inside the case, the printed circuit board is secured by plastic feet holding it tightly on the upper and lower horizontal sides. This means there can be no vertical adjustment of the board position to give the usual mechanical means of range control of the PIR. The operational mounting height of the unit however, is fairly flexible, specified as between 1.8m and 2.4m.
Installers wishing to conceal the feed wiring by tucking the detector tight under the ceiling can do so, although it should be noted that increasing the fixing height will of course decrease the effectiveness of the unit. For this purpose, a mounting bracket, BR-1, is separately available for pointing the unit downwards when sited at a height greater than 2.4m.
The wiring connections are via an eight-way terminal block along the top edge of the PCB. Connections are printed on the PCB using conventional terminology and installers will have little or no reason to consult the installation instructions since the set-up is self-explanatory. A six-core cable is the minimum requirement to provide for 12v DC supply, one normally closed anti-tamper pair and one normally closed alarm output pair.
A seventh terminal is provided labelled TST, to inhibit the walk test LED (apply hard -ve to inhibit) and a spare terminal marked EOL to park an end-of-line resistor if necessary. Two pairs of jumper pins are provided on the face of the PCB, the first to select the pulse count feature, calibrated at either one or two events in an unspecified time frame.
For the purposes of the test we used the two-event count throughout to achieve the greatest stability. The on-board walk test LED, which is displayed through a groovy crescent shaped lens, can be disabled altogether by the second two-pin jumper. The instruction leaflet incorrectly shows the jumper position reversed.
The 420 is a single pyro sensor PIR with no memory latch, anti-masking features or range adjustment, but it has to be said the trade price is very competitive and this model will appeal very much to installers looking for an inexpensive, reliable, no frills PIR.
Performance
The Digital name tag is a little disingenuous since pretty much all latter day PIRs have digital signal processing, and fuzzy logic is just a sexy way of saying the processor looks for a factory programmed ‘intruder’ type motion instead of simply a displacement of the heat pattern within the defined area. That said, the detector performed well enough throughout the test with good stability, though the 12m range was best achieved along the central axis – the areas to either side of this axis being slightly less sensitive with a little less detection range. The lens has only nine vertical segments or curtains of detection, which is rather on the low side when compared with other better specified PIRs. The nature of the ‘cylindrical’ lens does however give an effective look down or creep zone, with five lower placed vertical curtains. The device’s overall performance is commensurate with the unit cost.
We found the low current consumption to be exactly as per the quoted specification at 8mA, and though the detector is designed to operate at a nominal 12v DC, the voltage range is said by Scantronic to be usable from 9v – 16v DC. The normally closed relay output has an in-built resistance giving a consistent but curious reading of 32 Ohms, though the anti-tamper circuit output was much lower, at around 0.1 Ohm.
The horizontal spread of the detection pattern was close to 90 degrees. All the accompanying installation instructions are provided on both sides of a single A4 sized sheet with schematic diagrams for identification of parts and a coverage pattern for the PIR detection area. The instructions are good with installation guidelines in a diagrammatic form, and a troubleshooting guide. A specification is included with all the information required by an installer, i.e. current consumption, operating voltage, operating range and temperature requirements.
The product support telephone number is provided on the instruction sheet but beware – this is a premium number charged at 60p per minute! We spent a few minutes speaking to a product support engineer. He was technically knowledgeable and willing to chat – though perhaps that is not surprising at GB pound 36 per hour – including confirmation of our suspicion that this product was a joint research and development venture with Israeli manufacturer Visonic, whose ‘Next’ PIR bears far too much of a resemblance in design and concept to be a coincidence.
(Scantronic Registered Installers, who currently number some 2,500, are provided with a Freephone number – Ed)
What the manufacturer says …
The Scantronic 420 digital indoor motion detector uses passive infrared technology to detect movement of body heat to activate the alarm in the event of an intrusion. The 420 is suitable for the home, office or light commercial buildings. Designed to fit perfectly with any decor, the 420 is stylish and compact, extremely robust and very discreet.
It uses the latest digital technology and represents the future in signal processing and optical lens technology to lead the industry in detection accuracy, false alarm immunity and ultimate reliability. The 420 uses modern techniques which eliminate the many types of interference that affect reliability of traditional detectors to guarantee superior long term performance and dramatically reduce false alarms.
The Scantronic 420 uses 3D cylindrical lens technology that extends 12m 90 degree multiple solid vertical curtain coverage with uniform sensitivity detection. This provides wall creep zone coverage and eliminates any dead spots.
Fully sealed optics provide full protection against draught, dust and insect ingress, offering a high level of environmental immunity and reducing the burden from repeated false alarms.
Scantronic has designed the 420 to meet the most professional alarm installation standards and yet has made the product easy to install, with remote walk test saving installation time.
The 420 offers exceptional value for money with many features incorporated to give a high level of security benefit and total peace of mind.
