Ionisation Detectors
Ionisation detectors have some sensitivity to air movement
(wind). The extent to which the analogue value will change depends
on the wind speed and on the orientation of the detector relative
to the wind direction. Relatively small changes in wind direction
can cause significant changes in analogue value.
For wind speeds up to 1m/s (200ft/min) the change in analogue
value will not exceed 5 counts. Continuous operation in wind speeds
greater than 2m/s (400ft/min) is not recommended. However, wind
speeds up to 10m/s (2000ft/min) can be tolerated for short periods
and will not under any conditions increase the probability of false
alarms.