ENVIRONMENTAL INFORMATION MEASUREMENT DEVICE, ENVIRONMENTAL INFORMATION MEASUREMENT SYSTEM, AND ENVIRONMENTAL INFORMATION MEASUREMENT METHOD
This environmental information measurement device is provided with a power source unit, an environmental information detection unit, a timer unit, and a control unit. From received radio waves, the power source unit generates a power source voltage supplied to a load. The load contains the environmental information detection unit, timer unit, and control unit. The environmental information detection unit has a detection unit provided with a circuit element of which the impedance or capacitance varies in accordance with a physical quantity detected in the environment of a locus for measurement, and outputs a signal that varies in accordance with the response characteristics of the detection unit. The timer unit measures the time from the start of measurement until the voltage of the output signal reaches a predetermined detection voltage, and on the basis of said time, generates environmental information in accordance with the physical quantity. The control unit controls the operation of the environmental information detection unit.