Correction for the temperature effects in a pVTt gas flow primary standard employing a dynamic method

Primary standards in the field of gas flow rate metrology determine the change of mass in the system for a given collection time. Standards using the fixed volume volumetric method (pVTt) determine the mass by measuring the gas density inside a fixed volume. These standards usually use the static method of mass determination and rarely use the dynamic method as the gas temperature changes due to the density change. An analytical model predicting the temperature in a pVTt system was developed. The static and the dynamic methods were implemented, with the dynamic method including the temperature correction based on the model. The model was first validated using the pressure response during the flow rate measurement, followed by validation using a comparison between the measured flow rates using the static and dynamic methods. Based on the results, we believe that the corrected dynamic method is an alternative to the static method.