For instance, a quick rise in obscuration, without any associated rise in temperature, can be filtered out. Another benefit is that these detectors use algorithms to add the analog values from all of the sensors. The determination for reporting an alarm can then be based upon a combination of inputs from each sensing element, which further increases sensitivity. As smoke flows across a ceiling, it tends to affect more than a single detector. Multi-detector comparisons make use of this trend.
Affected detectors analyze adjacent detector pre-alarm conditions.
Alarms are initiated when the pre-alarm conditions of adjacent detectors indicate a similar rise in the associated value. This eliminates local spikes and allows decreased alarm thresholds. However, intelligent fire alarm systems can only provide additional information to the control panel and operator. Each building layout and environment is unique, and application of these systems should be evaluated to provide the best approach. Since an increase in the level of information is provided by analog detection, and given the ability of these detectors to compare conditions with known values, this technology has provided many enhancements to today's systems.