ClassiFire is a patented system which uses a powerful microprocessor to continually process statistical formulae and calculate the sensitivity and alarm thresholds for a predetermined maximum acceptable nuisance alarm rate. This rate, called the Alarm Factor, may be programmed for a theoretical value between 2 to 5000 years. The system also discriminates between 'dirty' and 'clean' operating periods such as day and night, automatically switching to the appropriate sensitivity and alarm thresholds for the environment.
The illustrations below show how ClassiFire builds up a smoke distribution pattern over time. The lower distribution is from a typical smoky environment such as a warehouse or office, while the upper is from a clean area such as a computer room or manufacturing clean room. Notice that although the same ClassiFire alarm factor ('n' in the illustration) is used in each case, the alarm thresholds are in different positions thus giving the optimum degree of protection for each area.
In a clean environment (top illustration) the histogram will tend to form at a lower mean level and with a smaller variance (the width of the distribution) than in a smoke filled environment (bottom illustration).
The numbered bar displayed represents the detector front panel bargraph which shows smoke density relative to the current mean. One of the advantages of ClassiFire over absolutely scaled systems is that only smoke levels above the mean detector level are displayed on the bargraph.
In these illustrations only one alarm level is shown for clarity. All of the Stratos range of detectors offer three levels of alarm to allow various stages of fire warning.
Another advantage of ClassiFire is that a blocked dust separator, which causes a reduced mean and smaller variance/deviation, will be automatically compensated for. When it is detected that the dust separator has reached the end of its useful life then a dust separator renew signal is generated by the detector. Dust separator condition can be viewed at any time.
For more information on interpreting the sensitivity of ClassiFire for comparing with other systems see the white paper Interpretation of 'sensitivity' for ClassiFire™
©AirSense Technology Ltd 2007