| 摘要 |
<p>PURPOSE:To avoid occurrence of false information due to noise in a hot-wire sensor. CONSTITUTION:An average value computing part 24 determines an average value of four consecutive data. By this averaging processing, white noise is removed. These average value data are made an absolute value by an absolute value attaining part 25 and this value is compared by a comparator 26 with a threshold value stored in a threshold value storage part 28. Only when all of the four consecutive average value data exceed the threshold value, the comparator 26 outputs an alarm signal SAL. In the other signal system, the data digitized by an A/D conversion part 30 are made an absolute value in an absolute value attaining part 31 and an average value of effective data in prescribed numbers is determined by an average value computing part 32. This average value represents an average level of noise, and based on this average value, the threshold value written in the threshold value storage part 28 is updated.</p> |
