A Method to Precisely Measure Ultrasonic Transmission Time

In accordance to the requirements of precisely measuring ultrasonic transmission time, a measurement method with high precision was proposed. The high-resolution A/D and high-speed FPGA were adopted as the core of hardware system to guarantee the instantaneity of ultrasonic echo. The sample data of entire ultrasonic echo were synthesized in software algorithm, and the arithmetic of software interpolation subdivision was employed to accurately calculate the end point of ultrasonic transmission time, so that the precision measurement of ultrasonic transmission time was ensured. Experiments show that, without increasing production costs, the method achieves the accuracy of measuring ultrasonic transmission time in nanoseconds level, even in picoseconds level.