GAS LEAKAGE ALARM DEVICE

• Main Authors: OZAWA TAKASHI, TOYODA KAZUO, SHIBATA MAKIKO, MATSUI HAJIME
• Format: Patent
• Language: English
• Published: 31.07.2003
• Edition: 7
• Subjects: ALARM SYSTEMS; ORDER TELEGRAPHS; PHYSICS; SIGNALLING; SIGNALLING OR CALLING SYSTEMS

PROBLEM TO BE SOLVED: To determine deterioration of a contact combustion type gas sensor by a secular change to high accuracy. SOLUTION: This device is provided with a mean value calculating means 1-2 obtaining an output value of a sensor means 1-1 at the time of no combustion gas in a surrounding area at specified time intervals until a preset prescribed period elapses and calculating a mean value of a plurality of the output values obtained at the present moment at specified elapsed time intervals, a minimum value detecting means 1-3 detecting a minimum value among a plurality of the mean values obtained at the present moment after the prescribed period elapses, a determining means 1-4 determining if the detected minimum value is deviated from a preset correction range or not as adding a prescribed value to the detected minimum value, updating and correcting a gas alarm determination value, an abnormality determining value determining abnormality of a contact combustion gas detecting element when determining the deviation from the correction range, and a setting means 1-6 setting the correction range between an initial value of the minimum value and the determination value preset based on the initial value of the minimum value to determine the deterioration of the contact combustion gas detecting element. COPYRIGHT: (C)2003,JPO