High precision, fast ultrasonic thermometer based on measurement of the speed of sound in air
High precision, fast ultrasonic thermometer based on measurement of the speed of sound in air
复制标题
基于空气中声速测量的高精度、快速超声波温度计
DOI：
10.1063/1.1510576
复制
发表时间：
2002
影响因子：
1.6
通讯作者：
M. Young
中科院分区：
文献类型：
--
作者：
K. Huang;C. F. Huang;Yan;M. Young
这项研究提出了一种基于微型计算机的超声波系统，它通过检测空气中声速的变化来测量空气温度。声速的变化是通过40千赫连续超声波的相移变化来检测的。在测试实施例中，两个40 kHz超声换能器以恒定距离面对面地设置。发射和接收信号之间的相角差由一个FPGA数字鉴相器确定，然后在89C51单片机上进行分析。温度被计算出来，然后发送到LCD显示器，也可以选择发送到PC。在传感器间距离为10厘米时，测量精度在0.05 °C以内。温度变化在10毫秒内显示。该系统具有分辨率高、测温速度快、非接触测量、易于实现等优点。
This study presents a microcomputer-based ultrasonic system which measures air temperature by detecting variations in the speed of sound in the air. Changes in the speed of sound are detected by phase shift variations of a 40 kHz continuous ultrasonic wave. In a test embodiment, two 40 kHz ultrasonic transducers are set face to face at a constant distance. Phase angle differences between transmitted and received signals are determined by a FPGA digital phase detector and then analyzed in an 89C51 single-chip microcomputer. Temperature is calculated and then sent to a LCD display and, optionally, to a PC. Accuracy of measurement is within 0.05 °C at an inter-transducer distance of 10 cm. Temperature variations are displayed within 10 ms. The main advantages of the proposed system are high resolution, rapid temperature measurement, noncontact measurement and easy implementation.