Patent attributes
The present invention prevents instability of frequency measurement caused by spatial connection between quartz sensors adjacent to each other when a plurality of quartz sensors, including a quartz resonator which varies a national frequency due to adsorption of an object, are to be detected. A common measuring unit measures a variation in frequency of each oscillation circuit corresponding to each quartz sensor by switching and connection in turn, and the oscillation circuits, excepting an oscillation circuit connected to the measuring unit by switches, are connected to a load on the output side of the oscillation circuit channels connected to the measuring unit and the load value is such that the respective oscillating frequencies are forcibly separated from each other.
