METHOD FOR QUANTITATIVELY DETERMINING MATERIAL OR ION TO BE INCORPORATED DURING NON-DEIONIZED WELDING AND CRYSTAL OSCILLATOR COATED WITH BARRIER ON ONE SURFACE TO BE USED IN THIS METHOD

PURPOSE:To make quantitative determination by coating one of both electrodes of the crystal oscillator with a barrier so as to prohibit the permeation of a non-deionized soln. via a specified insulating space and measuring the frequency while the crystal oscillator is held immersed into the non-deionized soln. CONSTITUTION:One electrode 2b of the electrodes 2a and 2b deposited by evaporation on a crystal plate 1 is coated by using the barrier formed by sealing, for example, a plastic plate 6, which is stable in the non-deionized soln., and, for example, silicone rubber 4, which are stable in the non-deionized soln., with polymer adhesive agents 3a and 3b of, for example, a silicone system, which is stable in the non-deionized soln. so as to prohibit the permeation of the non-deionized soln. to the insulating space 5, via the specified insulating space 5 while the tight contact with the electrode 2b is substantially averted. An adsorption film 7 is cast on the electrode 2a. The easy temp. control and stirring during the frequency measurement are possible in this way and the frequency is measured in the state of immersing the oscillator in the one-side barrier soln. without requiring a large-sized cell or a large volume of the non-deionized soln. and distilled water.