“The detectors performed very much as per manufacturer’s instructions, with a horizontal field of view of around 90 degrees. The current consumptions were low, at approximately 12 mA rising to 22mA upon LED activation.
“Each detector shared the same crescent shaped blue LED display to indicate relay change over, though the dual tech also gave indication of individual microwave and PIR activation, showing red and yellow outputs respectively.
“The concentration of elements in each fresnal lens is particularly dense, giving a total of 86 individual beams. Not surprisingly, this leads to excellent coverage and a quick catch in the PIR model, and installers should be mindful of just how ‘hot’ this PIR detector is (there is no pulse counting mechanism) and be careful to adjust the microwave sensor to its minimum effective range. Otherwise the advantages of a dual technology sensor are negated because the detector is so lively.
“In practice, it quickly became apparent the advantage of snap fitting the sliding front case into the wall plate was of no advantage at all, because engineers are unable to take live head voltage or relay output measurements. Furthermore, the team had reservations about the level of force needed to engage the front and rear cases and the consequent strength of fixing required to prevent the device being ripped off the wall.”