PURPOSE: To obtain an O2 pressure-division detector element of excellent response characteristics and good durability by the method wherein an electrode is formed by coating gold of specified thickness on the surface of platinum wires, a formed body of semiconductor oxide raw material powder is provided so as to surround and bury a part thereof, and then the entire structure is sintered.
CONSTITUTION: The surface of platinum wire is plated with gold in thickness of 0.5W5% of the diameter of the platinum wire. On the other hand, a green sheet is formed from a slurry made by mixing and kneading semiconductor oxide raw material powder of TiO2, butyral-resin, plasticizer and solvent, and small disks are punched from the sheet. Next, two pieces of gold-plated platinum wire 2 are placed at an interval of about 1.5mm in parallel between two disks and are bonded under pressure. Then, the entire body is sintered at a specified temperature (1250°C in the case of TiO2), and an oxygen gas pressure-division detector element is obtained. The gold and platinum react with each other at the sintering teperature, and a platinum-gold alloy in which gold is small in the inside is produced. Since the platinum is protected in this way, an element of excellent durability is obtained.
OOTANI MITSUHIRO
KUSAKABE KENJI
HIROI NOBUO
