Method and apparatus for measuring gas sorption and desorption properties of materials

Abstract

The invention relates to a method and an apparatus (herein referred to as a “gas sorption/desorption analyzer”) for measuring the gas sorption properties of substances (for example hydrogen sorption by metal alloys). Measurements include: Pressure Composition Temperature isotherm (PCT), Kinetic, Cycle-life, and density. Measurements are made by sorption of aliquots of gas to or from a sample of the substance. The amount of gas in each aliquot is determined from the gas pressure and temperature in calibrated reservoir volumes. The apparatus comprises components rated for operation up to 200 atm, a plurality of sensors covering a broad pressure range, and minimized volumes to enable accurate measurements of small samples. Aliquot pressures are controlled using a feed-back controlled pressure regulator that can also be used for constant pressure sorption measurements. The gas temperature is regulated using a temperature controlled enclosure. The apparatus also comprises a plurality of safety and failsafe mechanisms.

1 - 48 . (canceled) 
   
   
       49 . A gas sorption and desorption measurement apparatus comprising:
 a sample container;   a gas storage reservoir configured to hold a gas;   a first gas transmission line configured to couple with the gas storage reservoir to a gas supply source, the gas transmission line having a first gas valve;   a gas discharge line coupled to the gas storage reservoir, the gas discharge line having a second gas valve;   a second gas transmission line coupling the gas storage reservoir to a gas supply source to the sample container, the gas transmission line having a third gas valve;   an inlet gas pressure regulator, coupled to the gas storage reservoir, configured to deliver the gas to the gas storage reservoir; and   a computer configured to open or close the first, second and third valves to intermittently supply and discharge the gas from the gas storage reservoir to the sample container.   
   
   
       50 . The apparatus of  claim 49  wherein the inlet gas pressure regulator delivers the gas at a predetermined pressure. 
   
   
       51 . The apparatus of  claim 50  wherein the computer is further configured to control the inlet gas pressure regulator. 
   
   
       52 . The apparatus of  claim 51  wherein the inlet gas pressure regulator is PID regulated. 
   
   
       53 . The apparatus of  claim 52  wherein the predetermined pressure is a constant differential gas pressure above a measured gas pressure within the sample container. 
   
   
       54 . The apparatus of  claim 53  wherein at least one of the valves is actuated electrically or pneumatically. 
   
   
       55 . The apparatus of  claim 54  wherein the sample container further comprises a pressure failsafe mechanism configured to discharge a pressurized gas below a burst pressure of the sample container. 
   
   
       56 . The apparatus of  claim 55  wherein at least one of the valves close in the event of electrical power loss or of pneumatic control gas pressure.