Electronic pressure gauge for pressurized system with variable outlet flows

A method for determining the available duration of a gas in a gas cylinder comprising:

• providing a system comprising:
• a gas cylinder containing an amount of a gas;
• a gas outlet connector in fluid communication with said gas cylinder via a variable gas flow rate regulator settable to a plurality of gas flow rates;
• a variable resistance potentiometer;
• a pressure sensor;
• a processor;
• and
• a display;
• determining the gas pressure of said amount of gas in said gas cylinder using said pressure sensor;
• setting said variable gas flow rate regulator to a selected gas flow rate in said plurality of gas flow rates;
• detecting said selected gas flow rate with said variable resistance potentiometer;
• receiving at said processor:
• an indication of said selected gas flow rate detected in said detecting step;
• and
• an indication of said gas pressure determined at said determining step;
• calculating, using said processor, an estimated duration of said amount of gas in said gas cylinder based least in part on said indication of said selected gas flow rate and said indication of sensed gas pressure received in said receiving step;
• and
• displaying said calculated estimated duration of said amount of gas on said display;
• initiating a first alarm only if said calculated duration of said gas supply is below a first preset duration and said selected gas flow rate results in said gas pressure in said gas cylinder decreasing;
• and
• initiating a second alarm only if said calculated duration of said gas supply is below a second preset duration and said gas cylinder is not in use.