| الوصف: |
The light interference methane detector has many advantages, such as good stability, wide measurement range, etc. However, the artificial reading and poor level of automation make it no communication with monitoring system. To solve this problem, we report an improvement based on measuring the intensity of interferogram. The optical configuration was modified to guarantee the one-to-one relationship between the intensity of interferogram and the methane volume fraction. We used photoelectric elements to capture the interferogram and calculated the methane volume fraction with the variation of the interferogram intensity. Given that the zero-drift error was affected by environmental factors, we modeled the relation between pressure and measurement error by theoretical analysis, which was used to compensate the measurement error. Then the relationship between temperature and measurement error was determined experimentally. And we obtained the temperature compensating model by linear interpolation. At last, the effectiveness of compensating models and the stability of the designed system were verified by accuracy test, pneumatic test, temperature test and long-term stability test. |