The compact for pH measurement of pore water in soil and uses that the pH measuring method

摘要

PROBLEM TO BE SOLVED: To provide a molding, for pH measurement, by which the pH measurement of pore water, in a trace amount, in a compacted substance difficult to measure by a pH meter and a sheet of pH testing paper in conventional cases, the pH measurement of a solution containing much sludge, filth, suspension or the like and the pH measurement under a high-temperature and high-humidity condition can be performed simply and effectively and to provide a method in which a pH value can be measured by using the molding.;SOLUTION: Coloring particles in which a pH indicator is adsorbed to adsorbent particles are sealed up inside a protective sheet which is composed of a dialytic membrane, and a molding for pH measurement is obtained. The molding for pH measurement is left as it is in an object to be measured. After that, the coloring particles inside the protective sheet are taken out. A pH value is found on the basis of a change in the color of the coloring particles. Preferably, the change in the color of the coloring particles is measured by a colorimeter as a reflectance, and a pH value corresponding to the reflectance is found on the basis of a reflectance-pH value working curve which is created in advance.;COPYRIGHT: (C)2000,JPO