Studies on the p-v-t relations of fluids at high pressure II : the p-v-t relations of ammonia in the neighborhood of critical point and the critical values of ammonia

Using the variable volume method, the P-V-T relations of ammonia in the neighborhood of critical point have been measured within an error of 0.2% in regard to the compressibility factor Z. Seven P-V isotherms were obtained in the range of 131.05 to 133.96℃, 109.33 to 117.05atm and 53.42 to 110.22cc/mol around the critical point. The critical values of ammonia were determined from the isotherms as T_c=132.3℃, P_c=111.7atm and V_c=72.05cc/mol