Relative importance test equipment null of aqueous solution

摘要

PURPOSE:To measure the specific gravity of a sample with high exactness without the influence of the pH of the sample on the measured value by consisting the titled implement of a swellable material which exhibits the rate of water absorption corresponding to the ionic strength of the aq. soln. sample, a reagent layer contg. a material which generates a change in transparency by the solubility corresponding to the fluctuation width of the rate of water absorption and base. CONSTITUTION:The reagent layer 1 is obtd. by coating a coating soln. prepd. by dissolving the swellable material, water absorption indicating material, etc. on the base 2 and drying the coating. The swellable material may be any material of which the rate of absorption changes with the ionic strength of the aq. soln. sample and above all, a highly water-absorptive resin is particularly preferable as the rate of water absorption of said resin changes largely. The highly water-absorptive resin includes a starch/polyacrylic acid graft polymer, etc. The water absorption indicating material is preferably a material which is soluble in water and has high lightness when dried and is exemplified by tartrazine or the like which is transparent when dissolved in water.