RESIDUAL CHLORINE MEASURING DEVICE USING POLAROGRAPHIC METHOD

To provide a residual chlorine measuring device that can accurately measure residual chlorine concentration using a polarographic method even if the residual chlorine concentration is low.SOLUTION: In a polarographic residual chlorine measuring device using a pair of electrodes utilizing two or more electrodes including a counter electrode and an action electrode (a sensing electrode), and measuring residual chlorine concentration in water on the basis of an analytical curve representing a relation between an electrode current flowing between the counter electrode and the action electrode (the sensing electrode) and the residual chlorine concentration in water with a primary expression, as a changeover point where the residual chlorine concentration is prescribed concentration, the polarographic residual chlorine measuring device, a polygonal line analytical curve combining two analytical curves where an inclination of the analytical curve in a region where the concentration is equal to or below the changeover point is different from an inclination of the analytical curve in a region where the concentration is higher than the changeover point are used, in which in turn, the residual chlorine concentration in the water can be measured accurately even when the residual chlorine concentration is low or high.SELECTED DRAWING: Figure 4 【課題】残留塩素濃度が低い場合でも高い場合でも精度よく計測することが可能な、ポーラログラフ法を用いた残留塩素計を提供する。【解決手段】対極と作用極（検知極）を含む２つ以上の極を用いた１組の電極を使用し、その対極と作用極（検知極）との間に流れる電極電流と水中の残留塩素濃度との関係を一次式で表す検量線に基づいて、水中の残留塩素濃度を測定する、ポーラログラフ法を用いた残留塩素計において、残留塩素濃度が所定の濃度である切替点を境目として、その切替点以下の濃度の領域における検量線の傾きと、切替点より濃度が高い領域における検量線の傾きとが異なる２本の検量線を合体させた折れ線状の検量線を用いることにより、残留塩素濃度が低い場合でも高い場合でも、精度よく水中の残留塩素濃度を計測することができる。【選択図】図４