US Patent 12123794 Pirani gauge with model of power dissipation

A thermal conductivity gauge implements a model of power dissipation to accurately measure gas pressure. An envelope surrounds a gas volume, and a sensor wire is positioned within the gas volume. The controller provides a model of power dissipation from the thermal conductivity gauge, including power loss due to conductive heat loss from sensor wire end contacts, radiative loss from the sensor wire toward the gas envelope, and pressure dependent conductive heat loss from the sensor wire through surrounding gas. The controller then applies a power input to the sensor wire to heat the sensor wire, and measures total power dissipation W