Characterization of a controlled-clearance piston gauge using the Heydemann-Welch model

A study on the characterization of a controlled-clearance piston gauge was performed. In this study, the Heydemann-Welch model was used to define the controlled-clearance piston gauge as a primary pressure gauge. The parameters needed for the model were determined from measurements, and the characteristics of the controlled-clearance gauge were evaluated along with their uncertainty.