In the early 1980s, ultrasonic hardness testers were introduced to my country from abroad. Some domestic universities began researching the principles and structure of ultrasonic hardness testers, developing the first generation of domestically produced pointer-type ultrasonic hardness testers through university-industry collaborations.
These first-generation domestically produced ultrasonic hardness testers featured pointer displays and only possessed the technological level of Europe and America in the late 1960s. They suffered from low accuracy, high failure rates, and poor practicality. The second generation featured digital displays, also possessing the technological level of Europe and America in the late 1980s. They lacked curve fitting capabilities, only offering linear correction functions, resulting in low accuracy and poor quality. Until the early 21st century, high-end users in China still primarily relied on imported ultrasonic hardness testers from Germany and Japan.
Subsequently, Chinese manufacturers entered a stage of independent innovation. For example, Euro-Spectrum Instruments developed the OU2300 digital display ultrasonic hardness tester, which supports curve algorithms. Zhongwang Instruments developed and produced the OU2380 ultrasonic hardness tester, which supports curve algorithms, electric probes, and Bluetooth data transmission. Currently, some European manufacturers are using operating systems and touchscreen digital displays on their terminals, achieving multi-scale functionality.
