Anesthesia Technician Certification Exam 2 2026/2027 | Anesthesia
Equipment, Patient Safety & Certification Review Exam Questions and
Answers with Rationale
1. What is the primary function of the anesthesia machine's oxygen
failure safety shutdown (fail-safe) valve?
• A) To turn off the entire machine if electrical power fails
• B) To prevent the delivery of hypoxic gas mixtures by shutting off
or proportioning nitrous oxide when oxygen pressure drops
• C) To increase the pipeline pressure automatically during a crisis
• D) To purge excess nitrogen from the breathing circuit
• Correct Answer: B
• Rationale: The fail-safe valve ensures that nitrous oxide cannot
flow if oxygen pressure falls below a specific threshold, preventing
a hypoxic mixture.
2. Which color coding is standard for medical oxygen cylinders and
pipelines in the United States (CGA standards)?
• A) Green
• B) Blue
• C) Yellow
• D) Black
• Correct Answer: A
• Rationale: Under US CGA standards, oxygen is green (international
ISO standard uses white, but US standard is green).
,3. What color is designated for medical nitrous oxide cylinders in the
United States?
• A) Green
• B) Blue
• C) Gray
• D) Black
• Correct Answer: B
• Rationale: Nitrous oxide cylinders are color-coded blue in the US.
4. What safety system is used on high-pressure connections between
medical gas cylinders and the anesthesia machine yoke?
• A) Diameter Index Safety System (DISS)
• B) Pin Index Safety System (PISS)
• C) Quick-connect system
• D) Threaded adapter system
• Correct Answer: B
• Rationale: The Pin Index Safety System (PISS) uses a specific
configuration of pins and holes to prevent incorrect cylinder
placement.
5. What safety system is utilized for low-pressure hose connections
between pipeline outlets and the anesthesia machine?
• A) Pin Index Safety System (PISS)
• B) Diameter Index Safety System (DISS)
, • C) National Pipe Thread (NPT)
• D) Luer-lock system
• Correct Answer: B
• Rationale: DISS prevents accidental cross-connection of pipeline
hoses by using non-interchangeable diameter threads for each
gas.
6. At what approximate pressure (in psig) does a full, standard E-
cylinder of oxygen read on the pressure gauge?
• A) 50 psig
• B) 500 psig
• C) 1000 psig
• D) 1900 to 2200 psig
• Correct Answer: D
• Rationale: A full E-cylinder of oxygen contains compressed gas at
approximately 1900 to 2200 psig when full at room temperature.
7. Unlike oxygen, why does a nitrous oxide E-cylinder pressure gauge
remain constant (around 745 psig) until nearly all the liquid gas is
gone?
• A) Nitrous oxide is stored entirely as a compressed gas without
liquid.
• B) Nitrous oxide exists as a liquid and gas equilibrium inside the
cylinder; pressure drops only after the liquid phase is completely
vaporized.
, • C) The regulator automatically adjusts the pressure reading.
• D) Nitrous oxide pressure depends entirely on room humidity.
• Correct Answer: B
• Rationale: Nitrous oxide is stored under pressure as a liquid-vapor
equilibrium. Vapor pressure remains stable until all liquid is
consumed, meaning weight (not pressure) determines remaining
content.
8. What is the primary purpose of the variable-restrictive flow control
valves (rotameters) on an anesthesia machine?
• A) To measure patient blood pressure
• B) To control and display the precise flow rate of individual
medical gases delivered to the circuit
• C) To humidify incoming dry gases
• D) To scrub carbon dioxide from exhaled air
• Correct Answer: B
• Rationale: Rotameters regulate and indicate the flow of gases
(oxygen, nitrous oxide, air) in liters per minute (L/min).
9. Where should the oxygen flowmeter be positioned relative to other
gas flowmeters in a traditional bank to prevent a hypoxic mixture in
the event of a leak?
• A) Downstream (closest to the manifold outlet / nearest the
patient gas stream)
• B) Upstream (farthest from the manifold outlet)
Equipment, Patient Safety & Certification Review Exam Questions and
Answers with Rationale
1. What is the primary function of the anesthesia machine's oxygen
failure safety shutdown (fail-safe) valve?
• A) To turn off the entire machine if electrical power fails
• B) To prevent the delivery of hypoxic gas mixtures by shutting off
or proportioning nitrous oxide when oxygen pressure drops
• C) To increase the pipeline pressure automatically during a crisis
• D) To purge excess nitrogen from the breathing circuit
• Correct Answer: B
• Rationale: The fail-safe valve ensures that nitrous oxide cannot
flow if oxygen pressure falls below a specific threshold, preventing
a hypoxic mixture.
2. Which color coding is standard for medical oxygen cylinders and
pipelines in the United States (CGA standards)?
• A) Green
• B) Blue
• C) Yellow
• D) Black
• Correct Answer: A
• Rationale: Under US CGA standards, oxygen is green (international
ISO standard uses white, but US standard is green).
,3. What color is designated for medical nitrous oxide cylinders in the
United States?
• A) Green
• B) Blue
• C) Gray
• D) Black
• Correct Answer: B
• Rationale: Nitrous oxide cylinders are color-coded blue in the US.
4. What safety system is used on high-pressure connections between
medical gas cylinders and the anesthesia machine yoke?
• A) Diameter Index Safety System (DISS)
• B) Pin Index Safety System (PISS)
• C) Quick-connect system
• D) Threaded adapter system
• Correct Answer: B
• Rationale: The Pin Index Safety System (PISS) uses a specific
configuration of pins and holes to prevent incorrect cylinder
placement.
5. What safety system is utilized for low-pressure hose connections
between pipeline outlets and the anesthesia machine?
• A) Pin Index Safety System (PISS)
• B) Diameter Index Safety System (DISS)
, • C) National Pipe Thread (NPT)
• D) Luer-lock system
• Correct Answer: B
• Rationale: DISS prevents accidental cross-connection of pipeline
hoses by using non-interchangeable diameter threads for each
gas.
6. At what approximate pressure (in psig) does a full, standard E-
cylinder of oxygen read on the pressure gauge?
• A) 50 psig
• B) 500 psig
• C) 1000 psig
• D) 1900 to 2200 psig
• Correct Answer: D
• Rationale: A full E-cylinder of oxygen contains compressed gas at
approximately 1900 to 2200 psig when full at room temperature.
7. Unlike oxygen, why does a nitrous oxide E-cylinder pressure gauge
remain constant (around 745 psig) until nearly all the liquid gas is
gone?
• A) Nitrous oxide is stored entirely as a compressed gas without
liquid.
• B) Nitrous oxide exists as a liquid and gas equilibrium inside the
cylinder; pressure drops only after the liquid phase is completely
vaporized.
, • C) The regulator automatically adjusts the pressure reading.
• D) Nitrous oxide pressure depends entirely on room humidity.
• Correct Answer: B
• Rationale: Nitrous oxide is stored under pressure as a liquid-vapor
equilibrium. Vapor pressure remains stable until all liquid is
consumed, meaning weight (not pressure) determines remaining
content.
8. What is the primary purpose of the variable-restrictive flow control
valves (rotameters) on an anesthesia machine?
• A) To measure patient blood pressure
• B) To control and display the precise flow rate of individual
medical gases delivered to the circuit
• C) To humidify incoming dry gases
• D) To scrub carbon dioxide from exhaled air
• Correct Answer: B
• Rationale: Rotameters regulate and indicate the flow of gases
(oxygen, nitrous oxide, air) in liters per minute (L/min).
9. Where should the oxygen flowmeter be positioned relative to other
gas flowmeters in a traditional bank to prevent a hypoxic mixture in
the event of a leak?
• A) Downstream (closest to the manifold outlet / nearest the
patient gas stream)
• B) Upstream (farthest from the manifold outlet)
