高精度分体式多通道超声波温度计的设计

The Design of High Precision Split Type and Multi-Channel Ultrasonic Thermometer

针对传统的温度传感器在极端与特殊条件下无法满足测量的要求,设计了分体式多通道的超声波温度计。将多对测量头均匀布置在装有被测介质的容器外侧的各个方位,利用FPGA的控制驱动信号精确确定超声波传播的起点时刻,通过分块查找的特征波查找算法、高速高分辨率的信号采样电路和直线插补算法相结合,利用过零点两侧的采样点来实现对超声波传播时间终点时刻的高精度检测,进而精确计算出超声波传输时间。在传播距离一定的条件下,以水为介质为例进行模拟实验。结果表明:分体式多声道超声波温度计能够实现对超声波传输时间的分辨率ns级的测量,从而确保了对温度的高精度测量。

The traditional temperature sensor can＇t meet the requirements of measurement under harsh and particu-lar conditions,the split type and multi-channel ultrasonic thermometer is designed. Several couples of measuringheads are set in each lateral position of the containers of measured medium. The starting point of ultrasonic wavepropagation is accurately determined by control signal of FPGA. According to the combination of characteristicwave search algorithm through blocking search,the high-speed and high-resolution signal sampling circuit and lin-ear interpolation algorithm,utilizing the both sides of sampling point which close to zero point to complete the accu-rate detection of end time of ultrasonic wave propagation,and then precisely compute the ultrasonic transmissiontime. When propagation distance is definite,a simulated experiment with water as medium is accomplished,Resultshows that the split type and multi-channel ultrasonic thermometer can process ns level measurement of the resolu-tion of the ultrasonic transmission time,which ensuring high precision of temperature measurement.