How is a bulk nitrous oxide system characterized?

A bulk nitrous oxide system is characterized by the ability to store more than 3200 lb of nitrous oxide. This specification indicates that the system is designed for large-scale storage and supply of nitrous oxide, which is commonly used in medical settings for anesthesia and other applications. Systems of this scale are essential in hospitals and medical facilities where a continuous and substantial supply of nitrous oxide is required.

Storing more than 3200 lb allows these systems to meet the high demand for nitrous oxide in surgical and emergency situations, ensuring that medical professionals have access to the gas without interruption. Such systems typically have specialized storage and delivery mechanisms to manage the high pressures associated with the gas and ensure safe usage.

In contrast, the other options do not accurately describe a bulk nitrous oxide system. For example, the connection to a residential gas supply does not apply, as these systems are specifically designed for medical applications rather than residential use. Portable gas cylinders, while useful in certain contexts, pertain to smaller, transportable supplies rather than the bulk storage referred to in the question. Additionally, the use of liquid nitrogen is unrelated, as nitrous oxide and liquid nitrogen serve different purposes and are distinct substances used in medical and industrial applications.