| 摘要 |
PURPOSE:To obtain a detecting element having no variation in sensitivity due to SO2 and H2S which may cause the malfunction of a gas leak alarm, etc., by incorporating active alumina and active zinc oxide in the filter material of a detecting element. CONSTITUTION:The detecting element has a gas sensing body 3, coiled heater 4, and net 5 for explosion prevention on a base body 2 equipped with four pins 1. Two electrodes of the sensing body 3 are connected to two of electrode pins 1. The heater 4 is arranged surrounding the sensing body 3 and both its ends are connected to the two remaining pins. The net 5 covers the sensing body 3 and heater 4. The base body 2 is covered with a cap type filter 6 and no gas reaches the sensing body 3 without passing through the filter 6. When the filter 6 is formed, zinc oxide is crushed into particulates, mixing with ethyl silicate and ethanol to form paste, which is applied over the internal surface of a cap type active cap molding 7 and then dried, thereby sticking the active zinc oxide 8. |
