Component concentration measuring apparatus for developing solution, component concentration measuring method, developing solution managing apparatus and developing solution managing method

A component concentration measuring apparatus and method, a developing solution managing apparatus and a developing solution managing method are provided to measure or manage the concentration of absorbed carbon dioxide the alkaline developing solution. The component concentration measuring apparatus and the developing solution managing apparatus are provided with densitometers to measure the density of the developing solution. The density of the developing solution and the concentration of carbon dioxide have a good corresponding relation not influenced by concentrations of other components such as an alkaline component. The concentration of carbon dioxide is calculated by the component concentration measuring apparatus based on a measured density value and according to the corresponding relation between the density of the developing solution and the concentration of the carbon dioxide. Based on the corresponding relation between the density of the developing solution and the concentration of the carbon diox