Abstract: Disclosed is a system for measuring mass transfer in a membrane and solutions. The system includes: a membrane module 10 including a feed solution reservoir 11 accommodating a feed solution f, a draw solution reservoir 13 accommodating a draw solution d whose osmotic concentration is higher than that of the feed solution f, and a holder 15 supporting a semipermeable membrane m arranged between the feed solution reservoir 11 and the draw solution reservoir 13 and whose performance is to be measured; a feed solution storage tank 20 storing the feed solution f; and a feed solution supply pump 30 supplying the feed solution f from the feed solution storage tank 20 to the feed solution reservoir 11 at a fixed flow rate corresponding to a water flux WF across the membrane m such that the water flux WF is maintained constant.

Abstract: Disclosed is a system for measuring mass transfer in a membrane and solutions. The system includes: a membrane module 10 including a feed solution reservoir 11 accommodating a feed solution f, a draw solution reservoir 13 accommodating a draw solution d whose osmotic concentration is higher than that of the feed solution f, and a holder 15 supporting a semipermeable membrane m arranged between the feed solution reservoir 11 and the draw solution reservoir 13 and whose performance is to be measured; a feed solution storage tank 20 storing the feed solution f; and a feed solution supply pump 30 supplying the feed solution f from the feed solution storage tank 20 to the feed solution reservoir 11 at a fixed flow rate corresponding to a water flux WF across the membrane m such that the water flux WF is maintained constant.

Abstract: A pH measurement system using a glass pH sensor includes a power supply applying a voltage to the glass pH sensor through a resistor; a detector detecting the output voltage of the glass pH sensor; and a calculator calculating the pH of a solution based on the detected output voltage. The resistor provides a resistance of at least ten times less than the equivalent internal resistance of the glass pH sensor. The pH measurement system can improve the response rate by reducing the time constant depending on the dynamic characteristics of the glass pH sensor, and it is possible to diagnose whether the pH measurement system is defective or not by calculating the equivalent internal resistance and the supply voltage of the glass pH sensor.

Abstract: A pH measurement system using a glass pH sensor includes a power supply applying a voltage to the glass pH sensor through a resistor; a detector detecting the output voltage of the glass pH sensor; and a calculator calculating the pH of a solution based on the detected output voltage. The resistor provides a resistance of at least ten times less than the equivalent internal resistance of the glass pH sensor. The pH measurement system can improve the response rate by reducing the time constant depending on the dynamic characteristics of the glass pH sensor, and it is possible to diagnose whether the pH measurement system is defective or not by calculating the equivalent internal resistance and the supply voltage of the glass pH sensor.