| 摘要 |
<p>A calcined or sintered material having a basic composition (Pb1-xLax)(ZryTi1-y)1-x/4O3 (wherein O < x </= 0.25, O < y < 1) is pulverized and is used as a raw material for a support member of the moisture sensor. A plate made of this material having a thickness of 0.5 mm and a size of 6 x 6 mm is sintered at 800 to 1100 DEG C for several hours in the open air to obtain the support member. The support member is immersed in an aqueous solution of alkali metal phosphate of 0.05 mol/l or higher for several seconds, dried, and heat-treated at 600 DEG C to 900 DEG C for several hours in the open air so that the entire porous surface is covered with an alkali metal phosphate. As shown in Fig. 1, golden opposing electrodes (2) are formed on both surfaces of the moisture-sensing member (1) by vacuum deposition, and lead wires (3) are attached to the electrodes using an electrically conductive resin adhesive to obtain a moisture sensor of the sandwich structure. The sensor is left to stand several days under high-temperature and high-humidity conditions (60 to 90 DEG C, 80 to 95 % RH). At a temperature of 30 DEG C, the sensor exhibits an impedance of 1 M OMEGA when the relative humidity is 0 % and 3 M OMEGA when the relative humidity is 90 %, which is a region suited for assembling a measuring circuit, and further exhibits very little aging and very small temperature coefficient.</p> |
