Breathing Apparatus

Question 1

What is the composition of inhaled air?

Answer 1

Nitrogen (N2): 79%
Oxygen (O2): 21%
Carbon Dioxide (CO2): Trace

Question 2

What is the composition of exhaled air?

Answer 2

Nitrogen (N2): 79%
Oxygen (O2): 17%
Carbon Dioxide (CO2): 4%

Question 3

What are the respiratory hazards?

Answer 3

H: High air temperature
O: Oxygen deficiency
T: Toxic atmospheres
S: Amoke concentration

Question 4

BA Cylinder

Pressure?
Capacity in litres?
Fully charged air capacity?
Pressure tested at? How often?
Weight when full?

Answer 4

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

Question 5

What variables effect the BA’s working time?

Answer 5

• Lung capacity
• Fitness
• Temperature
• Anxiety
• Amount of work being done

Question 6

What is the calculation to determine actual working duration?

Answer 6

2040L/60Lmin - 10 minutes
= 34 - 10 minutes
= 24 minutes working time

Question 7

What is the flow capacity of the pressure reducer at full capacity?

Answer 7

700 litres per minute.

Question 8

What cylinder pressure activates the mechanical low pressure warning whistle?

Answer 8

55 plus or minus 5 bar.

Question 9

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

Answer 9

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.

Question 10

What is the first action you should take following a hardware failure alarm?

Answer 10

Exit immediately to a clean air environment.

Question 11

What is the term for the initial flow from the demand valve that allows air flow from the cylinder into the face mask?

Answer 11

First breath mechanism.

Question 12

What do the following HUD pressure status lights indicate?

4 green lights
3 green lights
2 green lights
1 yellow light
1 red light

Answer 12

• 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)

Question 13

What are the ratios for Biogard?

Answer 13

Concentrate: 1:80
Pre-diluted: 1:20

Question 14

What are the 5 steps to take when you have a faulty BA?

Answer 14

1. Notify your Officer-In-Charge
2. Remove the BA from the vehicle
3. Complete a ‘BA fault tag’ and attach it to the BA
4. Arrange for a replacement BA set (No. 38)
5. Send BA away as a complete unit.

Question 15

What are the signals for the following?

• Evacuation
• Quiet or cease operations
• Resume operations

Answer 15

Evacuation: 3 short blasts at one second duration each

Quiet or cease operations: 1 continuous blast for 3 seconds

Resume operations: 1 blast for 3 seconds, followed by a 1 second blast

Question 16

A BA set must not be placed on an appliance or in service if the pressure in the cylinder is below what?

Answer 16

250 bar

Question 17

List the 13 components.

Answer 17

Question 18

List the 13 components.

Answer 18

Question 19

What is the minimum preferable pressure of an operators cylinder to supply air for buddy breathing?

Answer 19

150 bar

Question 20

What is the total working time of a full cylinder?

Answer 20

24 minutes (10 minutes spare)

Question 21

How much time do you have when low battery power is indicated?

Answer 21

2 hours and it indicates 0-19% charge.