SEMICONDUCTOR MALODOROUS GAS SENSOR

• Main Authors: FUKUI KIYOSHI, TOSHIKAGE TERUKAZU
• Format: Patent
• Language: English
• Published: 11.01.1994
• Edition: 5
• Subjects: INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIRCHEMICAL OR PHYSICAL PROPERTIES; MEASURING; PHYSICS; TESTING

PURPOSE:To obtain a sensor having high sensitivity against a malodorous gas composed mainly of ammonia and low sensitivity against odorless gases by making a metal oxide semiconductor section to carry a strongly basic metal oxide and strongly acidic metal oxide together. CONSTITUTION:The sensor is provided with a metal oxide semiconductor section 2 on a platinum coil formed as a noble metal wire coil 1. The section 2 is made to carry a strongly basic metal oxide and strongly acidic metal oxide together. The basic metal oxide is composed of a lanthanum oxide and the acidic metal oxide is composed of a chromium oxide and, in addition, the adding amounts of the lanthanum and chromium oxides are set so that the ratio of lanthanum to chromium can become 8:2 to 1:9 and the total adding amount of lanthanum and chromium can become 0.03-10.0atm.% against the amount of tin contained in tin oxide. Therefore, a semiconductor malodorous gas sensor having high sensitivity against a malodorous gas composed mainly of ammonia and low sensitivity against odorless gases, such as the hydrogen gas, etc., can be obtained.