We develop primary standards of thermodynamic temperature based on acoustic and microwave measurement methods to realize and disseminate (Mise-en-Pratique) the new definition of the kelvin. We use these methods for the improvement of the International Temperature Scale and to develop novel thermodynamic standards of pressure and humidity. We measure the speed of sound in pure gases and mixtures over extended ranges of temperature and pressure for the determination of the thermophysical properties of substances having a relevant scientific interest.