Development of a Simultaneous Measurement System of Length and Temperature of Pipes Using Stationary Waves with Two Acoustic Sensors

在测量领域中，有许多应用，其中管道长度的测量起着重要的作用。从这个观点出发，开发了四种利用管内驻波的高精度管长测量系统。第一个系统测量具有开口端的管道的长度，第二个系统测量管道的长度，即使管道中的驻波被外部声音干扰，第三个系统不仅测量管道长度，而且测量分支管道的分支点的位置，最后第四个系统测量管道长度和管道中的温度。前三种测量系统是针对各种类型的管道开发的，考虑到管道中的温度是用温度计测量的，而最后一种测量系统是在考虑到管道中的温度变化如此之快以致于不能像在这种情况下那样由普通的温度计跟随的情况下开发的其中管道中的空气由空气压缩机加压。

In the field of measurement, there are many applications where the measurement of pipe length plays an important role. From the viewpoint, four types of highly accurate pipe length measurement systems were developed using stationary waves in the pipe. The first system measures the length of pipes with open ends, the second system measures the length of pipes even if stationary wave in the pipe is disturbed by external sounds, the third system measures not only the pipe length but also the location of branch point for branch pipes, and lastly the fourth system measures the pipe length together with the temperature in the pipe.That is, the first three measurement systems were developed for various types of pipes considering that the temperature in the pipe is measured with a thermometer, whereas the last measurement system was developed with the situation in mind that the temperature in the pipe change so rapidly as not to be followed by usual thermometers as in the case where the air in the pipe is pressurized by an air compressor.