| 摘要 |
PROBLEM TO BE SOLVED: To provide a chemical substance detection device having no problem of cost or a circuit design even if a high-speed vibrator is used, by solving the problem of cost increase or designing wherein when an oscillation frequency band of a vibrator becomes a high frequency band exceeding several-ten MHz, a low-cost TTLIC used in common at present cannot be used as it is. SOLUTION: This chemical substance detection device utilizing a piezoelectric oscillator is provided with: a piezoelectric oscillation circuit 7 for oscillating with a resonance frequency of the piezoelectric oscillator; and a fixed frequency oscillation circuit 9 for oscillating with a fixed frequency. In the device, an output frequency of the piezoelectric oscillation circuit is mixed with an output frequency of the fixed frequency oscillation circuit by an analog mixing circuit 11 so as to output a beat (resonance) frequency, and a beat component frequency is extracted by a beat extraction circuit 13, and then guided to a frequency counter circuit 15, thereby to count the frequency. COPYRIGHT: (C)2007,JPO&INPIT
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