Sensor module and measurement system

A sensor module comprising:

• a first piezoelectric resonator that has a first electrode;
• a second piezoelectric resonator that has a second electrode;
• an electrode cover that covers one of the first electrode and the second electrode;
• an oscillation circuit that drives and oscillates each of the first piezoelectric resonator and the second piezoelectric resonator;
• and a storage circuit that stores, as initial oscillation frequency information, information corresponding to i) a first oscillation frequency measured by causing the first piezoelectric resonator to oscillate upon shipment of the first piezoelectric resonator and ii) a second oscillation frequency measured by causing the second piezoelectric resonator to oscillate upon shipment of the second piezoelectric resonator, wherein at least one of the first piezoelectric resonator and the second piezoelectric resonator that is not covered by the electrode cover oscillates, when driven by the oscillation circuit, at a frequency corresponding to a thickness of a deposit deposited on a surface of an electrode that is exposed and not covered by the electrode cover.