A1-A2 Alarm Values

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

What is the concentration, in parts per million (ppm), that triggers the second alarm (A2) for Hydrogen Sulfide?

50 ppm

4.5 ppm

10 ppm

15 ppm (correct)

An oxygen level of what percentage would indicate an oxygen-deficient environment, triggering a first alarm (A1)?

19.5% (correct)

23.5%

10%

20%

Which gas has a first alarm (A1) value of 2.5 ppm?

Ethylene oxide

Carbon Monoxide

Hydrogen Cyanide (correct)

Organic Vapors

What is the second alarm (A2) value for methane, as a percentage of the Lower Explosive Limit (LEL)?

20% (D) Signup and view all the answers

Which of the following is NOT one of the 12 compounds detected by the Organic Vapor (OV) sensor?

Hydrogen Sulfide (B) Signup and view all the answers

An oxygen concentration at or below what percentage will trigger the A1 alarm, indicating a deficiency?

19.5% (D) Signup and view all the answers

What is the oxygen concentration that triggers the A2 alarm, indicating an oxygen-enriched environment?

23.5% (C) Signup and view all the answers

Which of the following describes the condition that triggers the A1 alarm for oxygen?

Oxygen deficiency (A) Signup and view all the answers

The A2 alarm for oxygen is triggered by what condition?

Oxygen enrichment (D) Signup and view all the answers

What is the difference in percentage points between the A1 and A2 alarm values for oxygen?

4.0% (A) Signup and view all the answers

Which of the following statements about the Lower Explosive Limit (LEL) of Methane is TRUE?

The LEL for Methane defines the minimum concentration required for a flammable mixture to ignite in air. (A) Signup and view all the answers

If the Methane concentration is 15% of the LEL, which alarm is likely to be triggered?

Only the A1 alarm will trigger. (A) Signup and view all the answers

What is the percentage difference between the Methane concentration that triggers the A1 alarm and the concentration that triggers the A2 alarm?

10% (B) Signup and view all the answers

If the Methane concentration is at 10% of its LEL, what can be concluded?

The A1 alarm will activate immediately. (D) Signup and view all the answers

Which of the following scenarios would NOT result in an immediate activation of the A2 alarm for Methane?

Methane concentration fluctuating between 15% and 25% of the LEL. (D) Signup and view all the answers

Which of the following best describes the relationship between the A1 and A2 alarm values for carbon monoxide?

The A1 alarm triggers at 35ppm, and the A2 alarm triggers at 50ppm. (D) Signup and view all the answers

If an environment has a carbon monoxide concentration of 40 ppm, what action is most likely?

The A1 alarm will be triggered. (C) Signup and view all the answers

Which statement is true regarding the progression of alarms for carbon monoxide?

The A1 alarm triggers first, and is then followed by the A2 alarm as the concentration increases. (D) Signup and view all the answers

What is the absolute difference in concentration, in ppm, between the two alarm levels for carbon monoxide?

15 ppm (C) Signup and view all the answers

What does it mean if an A2 alarm for carbon monoxide is triggered?

The carbon monoxide concentration is at or above 50 ppm. (A) Signup and view all the answers

What is the primary difference in operational response between the A1 and A2 alarms for Hydrogen Sulfide?

A1 initiates a lower level of awareness, while A2 signifies a more urgent condition requiring immediate action. (A) Signup and view all the answers

If a sensor reads 12.5 ppm of Hydrogen Sulfide, what is the most appropriate interpretation of this reading in terms of alarm status?

The A1 alarm will be active, but the A2 will not. (D) Signup and view all the answers

An environment is known to have a Hydrogen Sulfide concentration fluctuating around 13 ppm. Which statement is the most practically accurate regarding the alarm status?

The A1 alarm will predictably activate, whilst A2 is unlikely to be active. (C) Signup and view all the answers

What does the existence of two alarm levels for Hydrogen Sulfide (A1 and A2) most likely indicate?

They reflect a step-wise risk assessment, with A1 indicating caution levels, and A2 indicating a hazardous environment. (C) Signup and view all the answers

A technician observes that the A1 alarm for Hydrogen Sulfide is continuously active. What is the most probable immediate inference?

Hydrogen Sulfide concentrations are fluctuating around the A1 alarm level, necessitating monitoring. (C) Signup and view all the answers

What concentration of Organic Vapors, in parts per million (ppm), triggers the first alarm (A1)?

5 ppm (D) Signup and view all the answers

At what concentration of Organic Vapors, in parts per million (ppm), does the second alarm (A2) activate?

10 ppm (A) Signup and view all the answers

If the ambient concentration of Organic Vapors is measured at 8 ppm, which of the following statements would be true?

The A1 alarm is active, but the A2 alarm is inactive. (D) Signup and view all the answers

What is the difference in concentration, in ppm, between the A1 and A2 alarm values for Organic Vapors?

5 ppm (C) Signup and view all the answers

Which of the following is the correct relationship between alarm levels and corresponding concentrations of Organic Vapors?

A1 at 5ppm and A2 at 10ppm. (A) Signup and view all the answers

Study Notes

Safety Alarm Values

Oxygen (O2):
- A1 alarm (deficiency): 19.5%
- A2 alarm (enrichment): 23.5%
Lower Explosive Limit (LEL) - Methane:
- A1 alarm (low): 10%
- A2 alarm (high): 20%
Carbon Monoxide (CO):
- A1 alarm (low): 35 ppm
- A2 alarm (high): 50 ppm
Hydrogen Sulfide (H2S):
- A1 alarm (low): 10 ppm
- A2 alarm (high): 15 ppm
Hydrogen Cyanide (HCN):
- A1 alarm (low): 2.5 ppm
- A2 alarm (high): 4.5 ppm
Organic Vapors (OV):
- A1 alarm (low): 5 ppm
- A2 alarm (high): 10 ppm
- OV sensor detects 12 compounds:
  - Ethylene oxide
  - Propylene oxide
  - Ethene
  - Propene
  - Vinyl chloride
  - Methanol
  - Ethanol
  - Acetaldehyde
  - Butadiene
  - Formaldehyde
  - Vinyl Acetate
  - Isopropanol

Studying That Suits You

Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

Description

Test your knowledge on safety alarm values for various hazardous gases including oxygen, methane, carbon monoxide, hydrogen sulfide, and more. This quiz covers alarm thresholds and key definitions crucial for safety protocols in environments dealing with these substances.