METHOD DETERMINING MINIMAL DIAMETER OF PORES OF SPECIMEN Russian patent published in 2002 - IPC

FIELD: evaluation of quality of various porous materials. SUBSTANCE: method consists in that specimen is placed in cell dividing it into working and measurement chambers. Chambers are vacuum-treated, then working chamber is connected to atmosphere and oscillogram of change of pressure as function of time is drawn with recording of temperature and pressure change in working chamber. Point separating sections of mixed ( Knudsen and laminar ) and laminar outflows of gas and gas pressure in measurement chamber is determined by oscillogram. Minimal size of pores is found from relation where l is length of free path of molecules; K is Boltzmann constant (K = 1,38•10^-23J•K^-1), d_m is effective diameter of molecules of gas; T is temperature and P is pressure of gas in point separating sections of mixed and laminar conditions of gas outflow. EFFECT: raised precision of measurement of minimal sizes of pores. 2 dwg