Abstract: A tank simulator apparatus includes: a piping flowpath configured to receive a flow of a gas, the piping flowpath defining a buffer volume and including a receptacle for receiving gas flow at an upstream end thereof; a pressure transducer disposed in flow communication with the piping flowpath, the pressure transducer being configured to measure a pressure of the gas and generate a signal representative thereof; a pressure regulator disposed in flow communication with the piping flowpath and configured to maintain the pressure of the gas at a setpoint value; and an electronic controller operably connected to the pressure transducer and the pressure regulator, the electronic controller programmed to feed a time-varying setpoint value to the pressure regulator, the setpoint value following a tank profile representative of a tank having a predetermined volume.