Breathing Apparatus Flashcards
What is the composition of inhaled air?
Nitrogen (N2): 79%
Oxygen (O2): 21%
Carbon Dioxide (CO2): Trace
What is the composition of exhaled air?
Nitrogen (N2): 79%
Oxygen (O2): 17%
Carbon Dioxide (CO2): 4%
State 4 respiratory hazards a firefighter may encounter in a fire.
H: High air temperature
O: Oxygen deficiency
T: Toxic atmospheres
S: Amoke concentration
How does the closed circuit breathing apparatus function and what is the working time?
The cylinder holds compressed oxygen, carbon dioxide is absorbed by the equipment and unused oxygen is re-circulated.
These have a working time of up to 3 hours.
How does the open circuit breathing apparatus function and what is the working time?
Compressed air, in which carbon dioxide from users breath, is expelled to the atmosphere. Working time is 20-35 minutes depending on the working rate.
BA Cylinder
Pressure?
Capacity in litres?
Fully charged air capacity?
Pressure tested at? How often?
Weight when full?
Pressure: 300 bar
Capacity in litres: 6.8L
Fully charged air capacity: 2040 litres
Pressure tested at? 450 bar How often? Every 5 years
Weight when full: 7kgs
What variables effect the BA’s working time?
- Lung capacity
- Fitness
- Temperature
- Anxiety
- Amount of work being done
What is the calculation to determine actual working duration?
2040L/60Lmin - 10 minutes
= 34 - 10 minutes
= 24 minutes working time
What is the flow capacity of the pressure reducer at full capacity?
700 litres per minute.
What cylinder pressure activates the mechanical low pressure warning whistle?
55 plus or minus 5 bar.
What do the following buddy light status colours indicate?
Green
Yellow
Red
Green: 300 - 100 bar
Yellow: 99 - 60 bar
Red: 59 - 0 bar
How long will it take for the following alarms to activate and how do you deactivate them?
Pre alarms
Level 1
Level 2
Level 3
Full alarm
Level 4
Pre-alarms
Level 1: 17.5 seconds. Move the control module.
Level 2: 20 seconds. Move the control module.
Level 3: 25 seconds. Move the control module.
Full alarm
Level 4: 30 seconds. Press the reset button twice.
What is the first action you should take following a hardware failure alarm?
Exit immediately to a clean air environment.
What is the term for the initial flow from the demand valve that allows air flow from the cylinder into the face mask?
First breath mechanism.
What do the following HUD pressure status lights indicate?
4 green lights
3 green lights
2 green lights
1 yellow light
1 red light
- 4 green lights: 300 - 271 bar
- 3 green lights: 270 - 181 bar
- 2 green lights: 180 - 100 bar
- 1 yellow light: 99 - 60 bar
- 1 red light: 59 - 0 bar (flashing continuously until shutdown)