Honeywell MS-9200UDLSE Manual Do Utilizador

Operating Instructions

MS-9200UDLS   PN 52750:A    11/04/05

151

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.

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: 

Figure 4.1 illustrates a graphic representation of the maintenance levels:

Low Chamber Value

INVREP

A hardware problem in the detector

Maintenance Alert

DIRTY1

Dust accumulation that is near but below the 
allowed limit.  DIRTY 1 indicates the need for 
maintenance before the performance of the detector 
is compromised

Maintenance Urgent

DIRTY2

Dust accumulation above the allowed limit.

Maintenance
Urgent

Maintenance
Alert

Low Chamber   
Reading