What happens when the oxygen tank gauge indicates 500 psi?

When the oxygen tank gauge indicates 500 psi, it signifies that there is still a usable amount of oxygen available in the tank. Typically, oxygen tanks are considered to be usable when the pressure gauge reads above a certain threshold, which is usually well above 500 psi. This pressure level allows for continued operation and use in emergency situations, as there is still enough oxygen to support the needs required at that moment.

In terms of functionality, while the tank is not full--which would usually be indicated by a much higher pressure reading, often 2000 psi or more depending on the tank size--it still offers an adequate supply for various medical or emergency actions. Therefore, a reading of 500 psi suggests that the tank should still be operational but should be monitored closely, and it may eventually require filling or replacing, but it is not immediately classified as empty or needing replacement at this precise moment.