| 摘要 |
PURPOSE:To attain to stabilize the titled detector by providing such a simple structure that corrosive gas is not contacted with an oxygen detection element or a heater, by forming a pair of partition walls to the interior of a protective pipe having gas inlet and outlet provided to the lateral parts thereof so as to hold the gas outlet and inlet therebetween and arranging an oxygen concn. detection element to one of the partition walls while receiving the heating device and temp. detector of said detection element. CONSTITUTION:A gas inlet 22 and a gas outlet 23 are provided to the lateral parts of a protective pipe 21 inserted in gas and a pair of partition walls 24, 25 are provided so as to hold said inlet 22 and outlet 23 therebetween to form a measuring chamber 20. An oxygen detection element 1 is mounted to one partition wall 2 so as to allow the leading end part thereof to face to the measuring chamber 20 and an element main body 2 is provided with a cup shaped part 2a, a flanged leg part 2b and a plug 3 having a gas diffusion rate limiting hole 3a. The element 1 is heated to predetermined temp. through a heater 11 and a thermocouple 15 and voltage is applied between electrodes 4, 5 on ionize oxygen gas while the oxygen ion is flowed to an outside electrode through the element main body 2 and, from the current value thereof, the concn. of the oxygen in the gas diffused from the hole 3a is detected. Because corrosive gas is not directly contacted with the element 1 or the heater 11, the oxygen detection element can be used stably for a long period of time. |
