Patent ID: 8917078

Claim:
A frequency measuring device, comprising: a first resonator provided with a first adsorption film; a second resonator provided with a second adsorption film; a first oscillation circuit that outputs a first oscillation signal, the first oscillation circuit connecting to the first resonator, the first oscillation circuit being provided with a first frequency regulator, the first frequency regulator regulating a first frequency that is a frequency of the first oscillation signal; a second oscillation circuit that outputs a second oscillation signal, the second oscillation circuit connecting to the second resonator, the second oscillation circuit being provided with a second frequency regulator, the second frequency regulator regulating a second frequency that is a frequency of the second oscillation signal; a measuring circuit that measures the first frequency and the second frequency; a control circuit that controls the first frequency regulator and the second frequency regulator so that a difference between the first frequency and the second frequency becomes greater than a predetermined difference; a third resonator provided with a third adsorption film; a third oscillation circuit that output a third oscillation signal, the third oscillation circuit connecting to the third resonator, the third oscillation circuit being provided with a third frequency regulator, the third frequency regulator regulating a third frequency that is a frequency of the third oscillation signal; the measuring circuit measuring the third frequency, the control circuit performing: (a1) specifying a first signal that has the highest frequency of the first frequency, the second frequency, and the third frequency, and specifying a second signal that has the second highest frequency of the first frequency, the second frequency, and the third frequency, (b) comparing the highest frequency and the second highest frequency, (c1-1) specifying the second signal as a new first signal when a difference between the highest frequency and the second highest frequency is greater than the predetermined difference, specifying a signal having the second highest frequency next to a frequency of the new first signal as a new second signal, and returning to (b), and (c1-2) decreasing a frequency of the second signal by controlling one of the first frequency regulator, the second frequency regulator, and the third frequency regulator when the difference between the highest frequency and the second highest frequency is smaller than or equal to the predetermined difference, and returning to (a1).