Patent ID: 8024134
Filing Date: 2011-09-20
Classification: G01N

Abstract:
1. A gas sensor comprising: a plurality of gas detectors, each of which detects a target gas and is a reference detector or a regular detector; an error detector to detect an occurrence of an error on each of the plurality of gas detectors and send a result of the occurrence of the error to both an output selector and an output unit; said output selector selects one output in which no error exists from among outputs sent from each of the plurality of gas detectors; and said output unit receives an output signal from said output selector and generates a normal output based on the output signal when no error exists and outputs the normal output to an external electrical device through a single output system, wherein said output unit is configured to generate an abnormal output when the output of the error detector indicates that an error exists on one of the plurality of gas detectors so as to output alternately the normal output received from said output selector and the abnormal output based on the output of the error detector to the external electrical device through said single output system, wherein the range of the abnormal output to be supplied from the output unit is set outside the range of the normal output, and wherein the output device has a normal output mode, an abnormal output mode, and an intermittent output mode, in the normal output mode, the output device outputs a signal detected by the regular detector if no error exists in both the reference detector and the regular detector, and the output device outputs a signal detected by the regular detector if an error exists in the regular detector and does not exist in the reference detector and if a concentration of hydrogen existing in the reference detector is greater than a predetermined concentration, in the abnormal output mode, the output device outputs a signal indicating that an error exists in both the reference detector and the regular detector, in the intermittent output mode, the output device outputs alternately the signal indicating that no error exists in the reference detector and the signal indicating that an error exists in the regular detector if the concentration of hydrogen existing in the reference detector is lower than the predetermined concentration.