Acoustic signals
So that they can be heard, acoustic signals should be set at a level which is considerably higher in terms of frequency than the ambient noise, for example 10 dB above the level of ambient noise at that frequency. However, make sure the level is neither excessive nor painful. It is also important for signals to be easily recognisable, particularly in terms of pulse length and the interval between pulses or groups of pulses.
Ensure that acoustic signals are not used more than one at a time.
If a device can emit an acoustic signal at variable frequencies (this includes an intermittent signal operating on a discrete frequency) or constant frequencies, use the variable frequency set at 10 dB above the ambient level at the appropriate frequency to indicate a higher level of danger or a more urgent need for intervention or action.
Acoustic signals for fire alarms are covered in Part 3.
Keys Words :
So that they can be heard, acoustic signals should be set at a level which is considerably higher in terms of frequency than the ambient noise, for example 10 dB above the level of ambient noise at that frequency. However, make sure the level is neither excessive nor painful. It is also important for signals to be easily recognisable, particularly in terms of pulse length and the interval between pulses or groups of pulses.
Ensure that acoustic signals are not used more than one at a time.
If a device can emit an acoustic signal at variable frequencies (this includes an intermittent signal operating on a discrete frequency) or constant frequencies, use the variable frequency set at 10 dB above the ambient level at the appropriate frequency to indicate a higher level of danger or a more urgent need for intervention or action.
Acoustic signals for fire alarms are covered in Part 3.
Keys Words :
Comments
Post a Comment