Experimental Study On Performance Degradation Of MQ-3 Alcohol Gas Sensor

MQ-3 Alcohol gas sensors are widely used, not only because of their excellent properties such as high sensitivity, good stability, but also the low cost, which with strong market competitiveness. They are often used as the alcohol concentration detector, the alcohol concentration in the air can be detected. The nature of alcohol is very unstable, highly volatile, volatile alcohol steam mixes with air to form explosive mixture. Once the mixture exploded, it will bring irreparable damage to people's lives and property. So, whether it is alcohol manufacturing process steps, during storage or transport, we must do something like real-time detection of the alcohol concentration. In addition, the mistake of alcohol gas leakage alarm or omission alarm will bring serious consequences, so the accuracy of the monitoring results is essential. Therefore, alcohol gas sensor is required higher use time to avoid failure.There are two main methods of the common reliability evaluation for MQ-3 alcohol gas sensor. Including traditional test technology and accelerated test technology,comparing the two, accelerated testing technology needs less samples, and its test cycle is shorter, you can quickly get the reliability information of the samples which you need.In order to solve the above problems, this paper using Accelerated Degradation test(Accelerated Degradation Testing, ADT) to analyze the performance degradation process of MQ- 3 alcohol gas sensor,we design the test program, test data analysis,and evaluating performance index of the sensor. The main content of the research are as follows:First of all, the internal structure and the basic working principle of MQ-3alcohol gas sensor are analyzed, then the reliability of MQ-3 alcohol gas sensor is analyzed. We use the Failure Mode Effects and Criticality Analysis(FMECA)method to get the principal failure reasons of MQ-3 alcohol gas sensor, which is commonly used in security and reliability. And we use Fault Tree Analysis(FTA)method to determine the weaknesses of MQ-3 alcohol gas sensor.Secondly, we design the program of ADT, and determine the type of ADT.Considering the cause of failure, determining accelerated stress, including temperature, voltage and gas concentration, and cold and hot shock test. Specific steps under various stress test and announcements are introduced, and recording test data.Finally, the ADT data obtained were analyzed, the method based on the degradation path model is selected, and we establish the model of acceleration under different stresses. After setting the failure threshold, we can get the pseudo life and pseudo life distribution of MQ-3 alcohol gas sensor. Then we establish the parameters of pseudo life distribution using the least square method. We can get the Life relationship of the sensor under normal stress condition. And when the reliability is 0.9, the service life of MQ-3 alcohol gas sensor can be calculated.