The programming equipment for the measurement of weight changes over time is described. The measuring center consists of digital balances Precisa 200 A and microcomputer IQ 151 connected with a television set, tape recorder and plotter. The accuracy of measurement of these weight changes is up to 1 milligram/0.1 second. This method is suitable for the study of the initial phase of liquid penetration into porous material such as stone, mortar, etc.