The VESDA VLS by Xtralis is similar to the flagship VESDA VLP aspirating smoke detector but also includes a valve mechanism in the inlet manifold and software to control the airflow from the four sectors (pipes). This configuration enables a single VESDA zone to be divided into four separate sectors, for example, distinguishing between separate voids within a room. The VLS locates the origin of smoke by identifying the first sector (pipe) with the highest level of smoke and then continues to sample from all sectors to monitor fire growth. The VLS provides four alarm levels for each individual pipe (Alert, Action, Fire 1 and Fire 2). Sector factors (sensitivity) can be set individually to ensure the optimal alarm thresholds are applied for each sector. An extra LED indicates when the first alarm sector has been established.