Because this time is very dangerous, the user must not be forced to use. When approaching the danger fan vibration value, there will be vibration meter alarm. "Inflatable Air Blower" just started working low vibration bearing parts, but with longer, dust inside the fan operating time will be uneven attached to the impeller, the gradual destruction of fan balancing, bearing vibration gradually increased, Once the fan vibration reaches the maximum allowed by 11mm/s (with the amplitude value represents the maximum allowable value below), the fan must be shut down to repair (accumulation of dust cleared, redo balancing).