Abstract: A high pressure core chamber for use in collecting pressurized core samples from a reservoir is equipped with at least two high pressure access valves, allowing the core chamber to also function as a vessel for various high pressure experiments. In some embodiments, the core chamber is also equipped with a heater, allowing high pressure, high temperature experiments, and thus duplicating reservoir conditions. Various assays using the core chamber are also described.

Abstract: A device is disclosed for rapidly testing items for leaks. The device incorporates a mass concentration gauge. One such gauge has a sensor which has an .alpha.-emitting radioactive source to ionize gases in a space between two electrodes. Associated electronic circuitry is disclosed which automatically indicates when a leak is detected. Other gauges to measure mass concentration are disclosed which use sensors directed to dielectric variation, magnetic permeability variation, acoustic velocity variation and optical index of refraction variation. All sensors are sensing properties which are completely or relatively insensitive to temperature variations.