The Ei650iRF optical Smoke Alarm is fitted with a proprietary photoelectric sensor to quickly sense low energy smoke particles. This optical Alarm is sensitive to all domestic fire types but is especially sensitive to smoldering fires. The Ei650 range features a high performance optical chamber protected by a sealed mesh screen to reduce insect and dust contamination and EMC protection to reduce false alarms. In addition, the Ei650iRF has an automatic dust compensation feature reducing further the risk of false alarms caused by dust build up. The Ei650iRF communicates wirelessly via its preinstalled Ei600MRF RadioLINK+ module with compatible Ei Electronics Alarms and accessories. Up to 12 RF devices can be interconnected. The AudioLINK feature facilitates acoustic download of the Alarm parameters and status using the Ei Electronics AudioLINK app. For better hearing comfort, the sound level of the alarm increases progressively in Test mode. The Test button can also be used to silence nuisance alarms (e.g. cooking fumes) for a 10 minute period and fault beeps for 12 hours (low battery and sensor fault). The Ei650iRF self-checks its chamber sensor, battery voltage and internal circuitry every 40 seconds. Any fault condition found will be indicated by a combination of Yellow LED flashes and sound beeps. The Ei650iRF is designed with advanced diagnostics to help pre-warn of possible impending fault conditions. The Alarm has a twist on mounting base which has multiple fixing points so it can be easily installed. The alarm is not powered until it is twisted onto the mounting base, thus avoiding battery power consumption during storage and prior to installation.