Method of and apparatus for measuring electrolyte

An apparatus for measuring an electrolyte comprising

• a support table which supports a device for measuring ionic activity comprising an ion-selective electrode pair consisting of a pair of ion-selective electrodes, each of which is selectively responsive to the same ions, a pair of spotting holes through which a sample liquid and a reference liquid are respectively supplied to the ion-selective electrodes and a porous bridge which communicates the spotting holes with each other to permit the sample liquid and the reference liquid spotted to the spotting holes to electrically contact with each other, and positions the device for measuring ionic activity in a position where the sample liquid and the reference liquid are to be spotted to the respective spotting holes,
• a sample liquid spotting means including a sample liquid spotting tool which holds the sample liquid and spots the same to one of the spotting holes of the device for measuring ionic activity and a transfer mechanism which moves the sample liquid spotting tool between a spotting position where it spots the sample liquid to said one of the spotting holes of the device for measuring ionic activity positioned in said position and a retracted position away from the spotting position, and
• a reference liquid spotting means including a reference liquid spotting tool which holds the reference liquid and spots the same to the other spotting hole and a transfer mechanism which moves the reference liquid spotting tool between a spotting position where it spots the reference liquid to the other spotting hole of the device for measuring ionic activity positioned in said position and a retracted position away from the spotting position,
• the two spotting means being arranged so that one of the first and second spotting means first spots the corresponding liquid to the corresponding spotting hole in its spotting position and is removed away from the spotting position and then the other spotting means is moved to its spotting position to spot the corresponding liquid to the corresponding spotting hole within a chosen time after said one spotting means spots the corresponding liquid to the corresponding the spotting hole wherein the chosen time is set such that the lower limit thereof is the minimum time required to remove one spotting means away from its spotting position and to subsequently move the other spotting means to its spotting position, and the upper limit is determined based on the type of device used for measuring ionic activity.