What pressure does the intermediate system hold when the master switch is turned "OFF"?

• A. 45 psi
• B. 55 psi
• C. 100 psi
• D. 0 psi

Answer: (D)

The intermediate system of an anesthesia machine is responsible for delivering a consistent gas pressure from the gas storage to the various components of the machine. When the master switch is turned "OFF," it effectively disables the functioning of the machine, including its pneumatic components. Consequently, the pressure held in the intermediate system drops to zero psi, as there is no active gas supply or pressure created when the machine is not in operation. This is crucial for safety and ensures that no residual pressure is maintained in the system that could lead to accidental gas delivery. Understanding this behavior aligns with standard practices in anesthesia equipment management, emphasizing the importance of safely isolating the gas delivery system when it is not in use.