Underground Operations

Question 1

What is meant by the term “intrinsically safe”

Answer 1

The electrical design of the circuits are such that they will not produce an electrical sparks capable of producing an explosion

Question 2

What is meant by the term “intrinsically safe apparatus”

Answer 2

An apparatus in which all the circuits are intrinsically safe

Question 3

What is the LEL

Answer 3

Lower Explosive Limit - a concentration expressed as a percentage below which a flammable gas will not explode in air, but at or above which it will explode when simply exposed to air

Question 4

What is a SCBA

Answer 4

Self Contained Breathing Apparatus

Question 5

What is a SABA

Answer 5

Surface to Air Breathing Apparatus - a mask with a hose that goes to the surface - good for approx 300 ft

Question 6

What is the OSHA definition of a confined space?

Answer 6

any vessel, container, or room with a limited means of entry and egress, little to no ventilation, not intended for continual occupancy and where a potential for engulfment may occur

Question 7

What 7 things does our Gas monitors monitor and at what point will the alarm go off

Answer 7

O2 levels <19.5 and  >23.5
LEL 10%
Hydrogen Sulfide( H2S) - 10 ppm
Carbon Monoxide (CO) - 35 ppm
Carbon Dioxide (CO2) -  5,000 ppm
Airflow - if tube becomes bent or clogged (restricted)
Barometer

Question 8

At what interval should you report monitor readings

Answer 8

every 1-5 minutes

Question 9

What O2 reading indicates LEL may not be accurate

Answer 9

< 12%

Question 10

What factor can alter or give neg readings

Answer 10

Humidity

Question 11

What type of gas meter is used by the team

Answer 11

GasAlertMicro 5 IR