GDM Flashcards
What 4 substances can the GDM detect?
Hazmat - GDM
CO, CH4 (flammable gases for % LEL), O2 and H2S
What are the alarms for CO?
Hazmat - GDM
Alarm 1 -20 PPM (TWA)
Alarm 2 - 100 PPM (STEL)
What are the alarms for O2?
Hazmat - GDM
Alarm 1 - 19.5% (Low)
Alarm 2 - 23% (High)
What are the alarms for LEL%?
Hazmat - GDM
Alarm 1 - 10% LEL
Alarm 2 - 20% LEL
What are the alarms for H2S?
Hazmat - GDM
Alarm 1 - 5 PPM (TWA)
Alarm 2 - 10 PPM (STEL)
What do WEL, TWA & STEL mean?
Hazmat - GDM
WEL - Workplace exposure limit, which is divided into;
TWA - Time Weighted Average: Limit for exposure over period of 8 Hrs
STEL - Short Term Exposure Limit: Limit for exposure over period of 15 min
What alarms may the GDM sound, and how do you interpret them?
Hazmat - GDM
Alarm 1 - LOW and TWA
Alarm 2 - HIGH, OUT OF LIMIT & STEL
How can you interpret alarm 1
Hazmat - GDM
Alarm 1 - Beep, flash & vibrate: LOW (O2) or TWA identifier will be displayed.
How can you interpret alarm 2?
Hazmat - GDM
Alarm 2 - faster tones, flash and vibrate: HIGH, STEL or OL (over limit) will be displayed.
If an O2 Alarm actuates, what should the IC do?
Hazmat - GDM
Withdraw crews, inform control with reason and appropriate TM.
- If deficient, go to BA.
- If enriched, crews to remain vigilant for
increased flammability and associated
risks
If a LEL, CO or H2S alarm actuates, what should the IC do?
Hazmat - GDM
- Withdraw crews, inform control with
reason & appropriate TM. - Make L2 Hazmat
- If benefit outweighs risk, crews may be
recommitted in BA and with safe systems
for specific tasks
When should GDM be zeroed
Hazmat - GDM
Change of watch, before use and after use once interrogated
What consideration should be given when a H2S HIGH alarm is actuated?
Hazmat - GDM
Atmosphere may also be flammable.
