Oxygen system having sensors with a passive RFD interface

1. A passively powered gas sensor for remotely reading and transmitting a gas pressure of a system, comprising:

a hollow cylindrical body;

a stem axially aligned and extending outwardly from a first surface of the hollow cylindrical body, the stem having an interior surface and a threaded exterior surface, the stem including a path that permits a gas to enter only partially into the stem;

a pressure sensing element in the stem adjacent the path that permits a gas to enter only partially into the stem;

an antenna coupled to the pressure sensing element, where the antenna is located within the hollow cylindrical body and the stem;

wherein the pressure sensing device is polled remotely by a polling device, and powered by the polling device; and

wherein the passively powered gas sensor has no moving components and does not continuously monitor a pressure.

2. The passively powered gas sensor of claim 1 wherein the cylindrical body has a hexagonal profile.

3. The passively powered gas sensor of claim 1 , wherein the polling device powers the sensor with RF energy.

4. The passively powered gas sensor of claim 1 , further comprising a printed circuit board that carries the pressure sensing element, the printed circuit board disposed entirely within the stem.

5. The passively powered gas sensor of claim 1 , wherein the hollow cylindrical body is filled with encapsulating material.

6. The passively powered gas sensor of claim 1 , wherein the sensor can read pressures up to 2900 psi.