Read Status | Operating Instructions |
Drift compensation uses software algorithms that identify and compensate for long- term changes in the data readings from each addressable smoke detector. These long- term changes in detector data readings are typically caused by dirt and dust accumulation inside the smoke chamber. Drift compensation performs the following functions:
•Allows a smoke detector to retain its original ability to detect actual smoke and resist false alarms, even as dirt and dust accumulate
•Reduces maintenance requirements by allowing the control panel to automatically perform the periodic sensitivity measurements required by NFPA Standard 72
The FACP software also provides filters to remove transient noise signals, usually caused by electrical interference.
Maintenance Alert
The software determines when the drift compensation for a detector reaches an unacceptable level that can compromise detector performance. When a detector reaches an unacceptable level, the control panel indicates a maintenance alert. Table
4.1 summarizes the three levels of maintenance alert:
Maintenance Level | FACP Status Displays | Indicates |
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Low Chamber Value | INVREP | A hardware problem in the detector |
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Maintenance Alert | DIRTY1 | Dust accumulation that is near but below the |
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Maintenance Urgent | DIRTY2 | Dust accumulation above the allowed limit. |
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Figure 4.1 illustrates a graphic representation of the maintenance levels:
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| Alert |
LowChamber
Reading
LOW
151 |