Description
The Mercury is a battery-powered photoelectric smoke detector with a large test/hush button on the front face, a red LED alarm indicator, and an 85dB audible alarm output measured at 3 metres. The photoelectric sensor detects smoke particles by measuring light scatter within the detection chamber, giving early warning of smouldering fires before flames develop.
Designed for ceiling or wall mounting in hallways, landings, bedrooms and living rooms, the detector operates on a single 9V PP3 battery (supplied) and emits a low battery warning chirp when replacement is needed. The hush button reduces the detector's sensitivity for a ten-minute period when pressed, useful for silencing nuisance alarms triggered by cooking steam or shower vapour without fully disabling the unit. Mounting holes are spaced at 70mm centres, and the white ABS housing measures 101mm in diameter and 34mm deep.
Photoelectric detection is less prone to false alarms from kitchen or bathroom steam than ionisation-type detectors, making the Mercury suitable for installation near kitchens and bathrooms where ionisation models would trigger frequently. The unit conforms to EN14604:2005 AC/2008 and carries the CE mark. Operating temperature range is -10°C to +40°C, covering typical UK residential conditions. The static working current is below 12µA, giving a battery life of approximately one year under normal use.
Specification
| Battery |
1 x 9V PP3 (supplied) |
| Alarm output |
85dB @ 3m |
| Mounting hole centres |
70mm |
| Dimensions |
34mm x 101mmØ |
| Weight |
0.14KG |
| Static working current |
<12µA |
| Operating temperature |
-10 to 40°C |
Downloads
Product Manual
Frequently Asked
What is the hush button for?
The hush button reduces the detector's sensitivity for ten minutes when pressed. This silences nuisance alarms triggered by cooking steam or shower vapour without fully disabling the unit. After ten minutes the detector returns to full sensitivity automatically.
How does photoelectric detection differ from ionisation?
Photoelectric detectors sense smoke particles by measuring light scatter in the detection chamber. They respond faster to smouldering fires and are less prone to false alarms from cooking steam or bathroom vapour than ionisation detectors, which use a radioactive element to detect combustion particles.
How long does the battery last?
The 9V PP3 battery typically lasts around one year under normal use, given the detector's low 12µA static current draw. The unit chirps when the battery voltage drops below the operating threshold, signalling that replacement is needed.
Where should it be installed?
Install on the ceiling or high on a wall in hallways, landings, bedrooms and living rooms. The detector can be fitted near kitchens and bathrooms as photoelectric sensing is less prone to false alarms from steam than ionisation models. Avoid installing directly above cookers or in unheated outbuildings where temperatures drop below -10°C.