Ion concentration measuring device

An ion concentration measuring device obtaining a concentration of measurement ions by being provided in a measurement target containing the measurement ions and non-measurement ions, the device comprising:

• a measurement target power supply that controls a voltage of the measurement target;
• a measurement sensor unit that includes an ion trapping membrane selectively trapping the measurement ions to generate a voltage corresponding to the number of trapped measurement ions;
• a measurement membrane power supply that controls a voltage of the ion trapping membrane;
• and
• a power supply control unit that controls a size of a voltage to be output from each of the measurement target power supply and the measurement membrane power supply,
• wherein when polarity of the non-measurement ions is negative, the power supply control unit controls at least one of the measurement target power supply and the measurement membrane power supply such that the voltage of the measurement ion trapping membrane is smaller than the voltage of the measurement target.

An ion concentration measuring device obtaining a concentration of measurement ions by being provided in a measurement target containing the measurement ions and non-measurement ions, the device comprising:

• a measurement target power supply that controls a voltage of the measurement target;
• a measurement sensor unit that includes an ion trapping membrane selectively trapping the measurement ions to generate a voltage corresponding to the number of trapped measurement ions;
• a measurement membrane power supply that controls a voltage of the ion trapping membrane;
• and
• a power supply control unit that controls a size of a voltage to be output from each of the measurement target power supply and the measurement membrane power supply,
• wherein when polarity of the non-measurement ions is positive, the power supply control unit controls at least one of the measurement target power supply and the measurement membrane power supply such that the voltage of the measurement ion trapping membrane is larger than the voltage of the measurement target.

An ion concentration measuring device obtaining a concentration of measurement ions by being provided in a measurement target containing the measurement ions and non-measurement ions, the device comprising:

• a measurement target power supply that controls a voltage of the measurement target;
• a measurement sensor unit that includes an ion trapping membrane selectively trapping the measurement ions to generate a voltage corresponding to the number of trapped measurement ions;
• a measurement membrane power supply that controls a voltage of the ion trapping membrane;
• and
• a power supply control unit that controls a size of a voltage to be output from each of the measurement target power supply and the measurement membrane power supply,
• wherein the power supply control unit repeatedly performs
• a suppressing operation for suppressing infiltration of the non-measurement ions to the measurement ion trapping membrane by controlling at least one of the measurement target power supply and the measurement membrane power supply such that a difference between the voltage of the measurement target and the voltage of the measurement ion trapping membrane decreases, and
• a measuring operation for obtaining a voltage corresponding to the number of measurement ions trapped by the measurement sensor unit by controlling at least one of the measurement target power supply and the measurement membrane power supply such that the voltage of the measurement target and the voltage of the measurement ion trapping membrane have potentials different from each other.