| 摘要 |
Disclosed is a motion indicator with an oscillator (10) designed to generate a transmitted signal (12) and a signal processor (17) which compares the received signal (15) produced from the reflected transmitted signal with the transmitted signal (12) and, when a deviation in frequency is detected, generates an electrical signal (27), the motion indicator having a frequency or phase modulator (11) for the transmitted signal (12) in order to avoid spurious fault reports caused by interference in the same frequency band. |
