| 摘要 |
PURPOSE:To achieve easy and accurate measurement, by enabling the measurement of the temperature or pressure at the depth layer in vivo or the like utilizing an electromagnetic wave irradiated from outside as a power source of a sensor. CONSTITUTION:A sensor is buried into an object to be measured about the temperature. When an electromagnetic wave of 13.56MHz is supplied to the sensor through an antenna coil L1 from outside, a DC voltage is induced in both poles of a capacitor C2 and fed to the collector and the base of an oscillation transistor TR1 of a crystal oscillation circuit 1 via a resistance R1. Thus, the oscillation circuit performs oscillation at the resonance frequency of a crystal vibrator to radiate the output thereof outside through an antenna coil L2 for transmission. The temperature inside the body being measured can be measured by observing the frequency of the electromagnetic wave thus radiated with an external measuring device. |
