| 摘要 |
<p>PURPOSE: To self-diagnose whether a detection element is in the state or normal operation or not with a simple constitution with respect to the detector provided with a self-diagnosis function. CONSTITUTION: The output signal of a detection element 1 is inputted to first and second discrimination parts 5 and 6 through an amplifier 2, a filter 3, and an A/D converter 4. The first discrimination part discriminates detection of a body to be detected when the signal value exceeds a first reference value. When the mode is switched to the self-diagnosis mode, an amplifier gain control part 7 raises the gain of the amplifier. The second discrimination part discriminates that the detection element is not abnormal if the noise signal value of the detection element exceeds a second reference value; and it discriminates that abnormality occurs in the detection element if the noise signal value is equal to or smaller than the reference value.</p> |
