VESDA by Xtralis
VESDA VLI Product Guide
www.xtralis.com
7
2.2.1
Clean Air Zero
The Clean Air Zero feature is a process that directly measures the chamber clean air smoke reading.
This will reduce drift in the chamber smoke reading as caused by contamination.
The user can initiate the Clean Air Zero process using Xtralis VSC. It takes less than 60 seconds to
complete, during which time the detector is offline.
Clean Air Zero Process
1. The user executes the Clean Air Zero command in Xtralis VSC.
2. The main aspirator is turned off.
3. The Clean Air Zero aspirator located inside the chamber assembly is turned on. This aspirator
pumps clean air into the Chamber and purges any contaminated air.
4. After a waiting period, to allow the chamber to purge, a smoke reading is taken with clean air
in the chamber. This reading is the new clean air background value.
5. The Clean Air Zero aspirator is turned off and the main aspirator is turned back on.
6. An event indicating that the Clean Air Zero process has taken place is added to the event log.