9.5 Physical Environment Flashcards
What is the sound of a jet aircraft roughly
140db
The ear is sensitive to sounds between what frequencies?
20Hz - 20KHz
The brain can ‘filter out’ background noise through which type of attention?
Focussed attention
As a rule of thumb, when should you use a form of hearing protection?
When conversations cannot be heard clearly at 2 metres away
What is ‘illumination’
amount of light striking a surface
A control room must be lit by how much lux
300 lux
A corridor or walkway requires how much lux
50 lux
Studying an engineering drawing requires how much lux
750 lux
Why is vibration between 0.5Hz and 20Hz most problematic?
As the human body absorbs most of the vibratory energy in this range
Why is vibration between 50Hz and 150Hz worst for the hand?
As it is associated with vibratory-induced white finger syndrome (VWF)
What tools can generate vibration between 50Hz and 150Hz?
Pneumatic tools
artificial lighting is also known as
task lighting
what is the drawback of engineer using a torch
leaves engineer with only one hand available to work
What should be used instead of a torch?
light mounted on a headband
When can mobile access platforms become less stable
At heights
