超声测厚的简要历史回顾
The propagation of sound waves through air and other materials was studied as early as the nineteenth century, but the introduction of ultrasonic instruments required the electronic advances of the early twentieth century, including the development of the cathode ray tube. The idea of using ultrasonic waves to investigate the internal structure of materials was first investigated in the 1920s, and the first specific patent in the area of ultrasonic nondestructive testing dates to 1931. The first practical commercial ultrasonic test instrument, called the Reflectoscope, was patented by Prof. Floyd Firestone of the University of Michigan in 1940, and sonar development during World War II further advanced the field. In the 1950s, commercial instruments became widely available.
These early instruments were all developed primarily for ultrasonic flaw detection, although they could be used for thickness gauging as well. In the 1960s, the first smaller and more portable instruments designed for gauging began to appear, including instruments with digital thickness displays rather than oscilloscope screens. The Model 5221 introduced by Olympus' predecessor Panametrics in 1973 was the first commercial ultrasonic gauge that incorporated preset multi-mode measurement to cover a wide range of materials and thicknesses as well as switch-set velocity calibration.
Relatively compact, battery-powered instruments optimized for a wide variety of test applications became common in the 1970s, and instruments steadily became smaller and more powerful. Waveform displays as an operator aid and internal data logging were introduced in the 1980s, and in the 1990s digital signal processing replaced analog circuitry and improved stability and repeatability. Most recently, advances in microprocessor technology have led to new levels of performance in today's sophisticated, easy-to-use miniature instruments.
