Medical Gas and Pneumatic Systems Flashcards

A full oxygen E cylinder reads 2,000 psig. Using a cylinder factor of 0.28 L/psi and a flow of 5 L/min, about how long will it last?

Answer: 112 minutes

2,000 × 0.28 = 560 L, and 560 ÷ 5 = 112 minutes.

What is the DISS (Diameter Index Safety System) primarily used for?

Answer: Non-interchangeable low-pressure connections under 200 psig

DISS provides gas-specific threaded connections for low-pressure (<200 psig) medical gas equipment.

Which technology do most oxygen concentrators use to separate oxygen from room air?

Answer: Pressure swing adsorption with zeolite sieve beds

PSA concentrators use zeolite to adsorb nitrogen, producing roughly 90-96% oxygen.

Which oxygen sensor type generates its own current without external power and gradually depletes over time?

Answer: Galvanic fuel cell

Galvanic cells produce current from a chemical reaction and are consumed over their service life.

A two-point calibration of an oxygen analyzer is usually performed using which reference gases?

Answer: Room air (20.9%) and 100% oxygen

Room air at 20.9% and pure oxygen bracket the clinical measurement range.

An air-oxygen blender sounds an audible alarm during use. What is the most likely cause?

Answer: A significant pressure imbalance between the air and oxygen inlet supplies

Blenders alarm when inlet pressures differ substantially (about 20 psi), which compromises mixing accuracy.

Why must oil and grease never be used on oxygen regulators or fittings?

Answer: They can ignite spontaneously in high-pressure oxygen

Hydrocarbons in an oxygen-enriched, high-pressure environment can ignite violently.