Thermal pressure control: regulation of high-pressure gas by exploitation of temperature sensitivity

Precise pressure regulation in high-pressure gas-filled vessels is made difficult by the pronounced temperature dependence of gas pressure. The paper proposes an unusual control system exploiting the gas pressure-temperature relationship to achieve unusually precise regulation in a 207 MPa (30,000 lbf/in²) gas-filled test vessel for rock physics measurements. Joule-Thomson cooling, a major dynamic effect, is also discussed. This paper is presented as a conceptual and theoretical development