| Abstract: | The speed of sound in gaseous refrigerants R-134a and R-507a is measured by the method of ultrasonic interferometer in a temperature
interval from 293 to 373 K and pressure values from 0.01 to 0.5–2.9 MPa. The errors in measurement of the temperature, pressure,
and speed of sound are ±20 mK, ±4 kPa, and ±(0.1–0.2)%, respectively. On the basis of the data obtained, the temperature dependence
of the idealgas heat capacity is calculated. The results obtained are compared with calculation of speed of sound from the
fundamental state equation for Helmholtz free energy. |
