The bench test 2: Eastern promise

What our experts say …
THIS DETECTOR HAS BEEN TESTED, according to the manufacturer's press release, "in the highly demanding environmental conditions of high ambient temperatures and humidity, along with frequent electric storms, in the Far East". We carried out our usual range of tests in slightly less exotic surroundings!

The QTEC XQ, a dual technology volumetric detector, has been recently introduced by Xeridyne Security Products as one of a range of "new tech-nology" detectors designed to provide the highest standard of immunity to false alarm situations.

It incorporates an X-band microwave frequency (5.2 – 10.9 GHz range) section and a PIR section. When both sections are activated within a time window of 10 seconds, an alarm is generated.

The PIR section uses a quad element pyroelectric sensor, along with a white fresnel lens, to give coverage of 88 degrees out to a range of approximately 15 metres. Maximum range is obtained when mounted at a height of 2.4m – once mounted, there is no adjustment for changing the range coverage.

A "combi" mounting bracket is available for either wall or ceiling mounting which allows adjustment of up ten degrees maximum from vertical and through 90 degrees horizontally.

The microwave coverage range is adjustable from a maximum of 15m down to 5m. The manufacturer recommends that it should be set to match the protected area, since microwave signals can pass through walls. Reducing the range setting will avoid response to the movement of external solid objects and reduce the probability of a false alarm occurring.

The triggering of each section is individually indicated by separate LEDs, with a third LED for alarm indication. The alarm output is given via a solid state relay rated at 16 volts DC, 250mA.

The LEDs can be disabled by removing an internal link in order to avoid surreptitious walk testing by undesirables. Provision has been made for remote enabling.

Construction
The QTEC XQ has been designed for ease of instal-lation with all the components mounted on a single removable PCB which, at just 87 x 47mm, must be one of the smallest on the market. The PCB is firmly held in the base of a two-part ABS enclosure by two plastic hooks and a single plastic clip.

Cable entry and securing sections are moulded into the base, blanked off by a thin layer of base material. A section shaped to accommodate the "combi" mounting bracket is also included; this has a rack for positively locating the detector on the bracket so that, once secured, the QTEC cannot be easily displaced. The white, domed fresnel lens is clipped onto the cover, which includes a hood to surround the quad element sensor and light pipes for the surface mount LED outputs which are visible through the lens. The cover hooks on the top of the base and latches securely at the bottom. A screw is provided for extra tamper resistance.

Outwardly, the QTEC XQ is very neat and stylish; inwardly it is well designed with a high quality PCB.

Installation
The front cover is removed from the base by inserting a small flat-bladed screwdriver at the bottom end to release the latch. Contrary to the impression given in the instruction sheet, the PCB retaining clip requires a bit more than a gentle push in order to allow PCB removal.

   The clip is not likely to snap off since movement is restricted by a rib moulded into the base.

The appropriate mounting and cable entry holes can be opened up, avoiding the removal of an excessive amount of base material. The usual six-core cable can be used for supply, alarm and tamper connections but if the remote LED enable feature is to be used then an additional connection will be required to connect a switched 0 volts to the appropriate terminal.

When replacing the PCB in the base, it is essen-tial to ensure that the hole in the circuit board is aligned with the dowel in the base in order to allow the PCB to be snapped under the securing clip.

Performance
We mounted the QTEC XQ at a height of 2m in order to carry out walk tests and to assess stability. Under our test conditions, at an ambient temperature of 15 deg C, it performed exceedingly well during walk tests and the stability tests.

The stability tests were carried out with the microwave detection area adjustment setting at maximum (fully clockwise), as supplied.

The movement of a person outside the test area did trigger the microwave section; this was avoided by reducing adjustment setting sufficient to retain alarm response within the protected area.

The manufacturer's Installation Instructions are printed on a single-sided A4 sized sheet and are quite adequate for the intended purpose.

They include a specification and PIR section coverage pattern, installation, setting up and testing instructions, along with clearly annotated diagrams.

Under the General paragraph, installers are reminded of the basic recommendations for siting detectors – sufficiently brief that we even read them!

Appendix A "Fitting the Combi Bracket" shows a diagram of the bracket in bits and assembled along with detailed instructions.

What the manufacturer says ...
THE QTEC XQ HAS FEATURES DESIGNED TO provide the highest standard of immunity from false alarms, coupled with unrivalled catch performance over the full protected area, using the most advanced materials and software available, including:

• A new lens material which has higher infrared transmission properties than any currently used in the industry worldwide. A higher level of transmission means that less signal amplification is required and thus the unit is less susceptible to RF interference.

• The design incorporates microprocessor controlled digital circuitry with software controls to screen out false alarm conditions. This is far more sensitive than analogue circuitry and is achieved using Xeridyne's unique SERA (Spurious Event Rejection Algorithm) technology.

• X Engine Software – Unique to the Microwave Doppler radar processor in the QTEC dual technology product. Normally a Doppler Radar is most sensitive to movement towards or away from it, whereas a PIR is most sensitive to movement across the field of view. Since the product uses both technologies monitoring the same field of view and to generate an alarm event, it is desirable for both technologies to have the same response.

• The X Engine Software processes the Doppler signal in a unique way that makes the microwave technology more sensitive to movement across its field of view, thus matching the PIR response. This increases sensitivity and eliminates responses to repeating interference such as from fluorescent lights, thereby removing the need for filtering circuitry that degrades performance.

• By using solid-state relays the units are not vulnerable to magnetic interference or tampering by proximity to a strong magnetic field.

• The QTEC XQ is designed to exceed the new, more stringent electrical performance requirements about to be introduced.

• The QTEC XQ has the best price/performance balance available.