Surface tension measuring method and concentration controlling device utilizing a surface tensiometer

摘要

A surface tensiometer including a measurement container having an upper edge opened horizontally and communicated with an end of a connecting pipe, an inlet container having an upper edge opened at a position higher than the upper edge of the measurement container and communicated with the opposite end of the connecting pipe, and a measuring device. The measureing device is operable to measure an altitude of a highest position of a concave liquid surface statically formed in an equilibrium between an upward force exerted by a pressure difference due to an altitude difference between a liquid surface of said measurement container with the liquid surface being raised from the opened upper edge of the measurement container after the liquid introduced from the inlet container reaches and overflows from the measurement container and a liquid surface of the inlet container and a downward force exerted by a surface tension of the raised liquid surface per se. There is also disclosed a concentration control device for controlling a concentration of liquid constant by utilizing the detection of the concave liquid surface by the surface tensiometer.