Nilfisk-Advance America GB 1133 - Manual (Page 13)

10 Monitoring the airflow
All Nilfisk vacuum cleaners - except category of application “U“ -
are fitted with a manometer that allows you to monitor the
minimum airflow in order to guarantee an optimal air speed
within the suction hose. When you lift the floor nozzle into the
air and the manometer’s pointer turns from the green into the
red zone, the main filter needs to be cleaned or the dust bag
is full and needs to be replaced.
Extractors
When the cutoff point is reached, the dust-producing system is switched off
automatically and the red warning light flashes up. Clean the main filter or replace the
dust bag.
The fill level of the dust bag/dust collecting container has to be checked at regular
intervals. Monitoring the fill level/automatic gear change (extractors) is no guarantee
that the bag is not full.