| 摘要 |
PURPOSE:To measure the temperature with high precision and high resolution in a very low temperature area by utilizing the insertion loss of a crystal resonator having the large temperature coefficient in the very low temperature area and improving the temperature resolution. CONSTITUTION:A crystal thermometer is composed of the crystal resonator 1 with about 40kHz of the natural frequency through a production process of photolithography, an AGC amplifier 2 generating the self-excited vibration for this crystal resonator 1, a counter 3 detecting the resonant frequency of the crystal resonator 1, an arithmetic circuit 4 detecting the insertion loss and an arithmetic circuit 5, etc. calculating the ambient temperature. Then, the crystal resonator 1 generates the self-excited vibration by the amplifier 2 and makes the bending vibration and the counter 3 detects its resonant frequency and the arithmetic circuit 4 detects the insertion loss. Further, the arithmetic circuit 5 calculates the ambient temperature from the natural frequency and in case the temperature is lower than 20 deg.K, the temperature can be measured with high precision by calculating the ambient temperature based on the insertion loss. |
