GAS SENSOR WITH FILTER

PURPOSE:To decrease the extension of the response time of a gas sensor and to obviate the clogging of filters by providing inside and outside filter media, holes of the inside filter medium, aperture, passages, etc. CONSTITUTION:The gas which is naturally diffused enters the 1st passage formed between the outside filter medium 2 and the inside filter medium 1 through the aperture 4 as shown by an arrow. The gas moves between the media 2 and 1 at the flow rate limited by the hole 3 bored to the medium 1 and passes through the hole 3 as shown by an arrow B to the inside of the medium 1, thus arriving at the gas sensor 5 by passing through the inside space 7 which is the 2nd passage. A poisonous material contacts incessantly with the filter media during the time when the gas traces such route and since the number of the contact is increased, such material is adsorbed by the filter media and is removed. Only the sensing component arrives at the sensor 5. The response time is thus decreased and the deterioration in the function is obviated.