Which gauge indicates the pressure of the gas in the auxiliary oxygen cylinder when in use?

• A. Auxiliary Tank Pressure Gauges
• B. Hospital Pipeline Pressure Gauges
• C. Flowmeters
• D. Reservoir Bag

Answer: (A)

The key idea is understanding where each gauge reads from on the anesthesia machine. The oxygen cylinder stores gas at very high pressure, and the gauge attached to that cylinder directly measures the pressure inside the cylinder itself. This tank/auxiliary cylinder pressure gauge tells you how much gas is left in that specific cylinder and when you need to replace or switch sources.

In contrast, the hospital pipeline pressure gauge shows the pressure of the incoming gas from the wall supply, usually a stable, relatively low pressure. Flowmeters indicate the chosen flow rate of gas sent to the patient after regulation, not the amount of gas remaining in a cylinder. The reservoir bag is part of the breathing circuit and does not provide a pressure reading.

So, the gauge that indicates the pressure of the gas in the auxiliary oxygen cylinder while in use is the tank/auxiliary cylinder pressure gauge.