The early days of vibration level meter developmentWith the passing of the Basic Law for Environmental Pollution Control in 1967, noise and vibration were included in the seven typical pollutants along with air pollution, water pollution, soil contamination, ground subsidence, and offensive odors. At that time, the measurement criteria and evaluation indices had yet to be standardized. The turning point arrived in 1968 with the establishment of JIS C 1510 ‘Vibration level meters’ and JIS Z 8735 ‘Methods of Measurement of Vibration Levels’ based on numerous surveys and studies led by the Environment Agency, with signicant contributions from Dr. Sakae Morita, Dr. Yasuo Tokita, Dr. Juichi Igarashi, and the Kobayasi Institute of Physical Research (from which Rion was founded). The establishment of these standards gave Rion a head start on developing commercial vibration level meters. A common vibration meter (acceleration sensor) simply calculates changes in amplitude and frequency as a physical quantity. In contrast, our vi-bration level meters feature the quantication of vibration as vibration level Lv (unit: dB), calculated as a product of the measured vibration and human vibration perception.I asked one member who participated in the development of the vibration level meter about its history.“About half a century ago, vibration level meters were developed in Japan in response to the emerging social issues of the time. The Japanese Industrial Standards (JIS) were the world’s rst to establish standards for product performance. The measuring instruments, evaluation methods, regulatory standards, and limits were all stipulated in the Vibration Reg-ulation Act. Vibration level meters are also included in the Measurement Act. Rion has been involved in the development and dissemination of vibration level meters since the very start. The related technology and knowledge have been passed on from generation to generation at Rion, and have evolved to meet the changing needs.”Rion’s world-changing technologies and conceptsIn 1967, Rion marketed the VM-12 vibration meter for pollution mea-surement as a vibration meter dedicated to measuring vibration pol-lution. It featured not just vibration perception characteristics, but time-weighting characteristics in Fast and Slow modes and even units of velocity. Released in 1974, the VM-14B vibration level meter conformed to JIS standards and became a legendary product, the rst of its kind to receive type approval. The model had three sensitive axes in the vertical and horizontal directions. It was capable of measuring vibrations from 30 dB, below the threshold of human perception.“The Japanese standard, JIS C 1510 ‘Vibration level meters’ was es-tablished in 1976. Two years before this, ISO 2631 ‘Evaluation of human exposure to whole-body vibration’ was established as an international standard. I’ve heard that the results of research by Japanese researchers and engineers prior to this had won high acclaim overseas and con-tributed signicantly to establishing the international standard by the International Organization for Standardization (ISO). I’m proud to have taken part in the development of vibration level meters. Since then, Rion has made steady advances in its vibration level meters in response to prevailing trends and advances in technology.”[VM-12] (1967)The VM-12 was developed primarily to measure ground vi-brations for vibration pollution surveys. Designed to com-ply with draft vibration level standards proposed by the Acoustical Society of Japan, it allowed the direct reading of vibration velocity and vibration acceleration, in addition to providing numerical values reflecting human percep-tion. The lower measuring limit was 45 dB. This model was a predecessor of modern vibration level meters.[VM-14B] (1974)This model was the first to receive type approval as a vibration level meter. The PV-83 vibration pickup weighed about 800 grams. The device featured a maximum value holding function.[VM-16] (1976)This vibration level meter allowed simultaneous mea-surement in three vertical-horizontal directions. Its three input channels allowed simultaneous measurements at three points, which also allowed observation of vibration damping with distance. It operated on any of three power sources: batteries, AC power supply, or DC power supply.8Toshiyuki HasumiIn the nearly 20 years since he joined Rion, Toshiyuki Hasumi has contributed to the development of vibration and sound level meters. He played a key role in the development of the VM-53/VM-53A vibration level meters and the VM-54 three-axis vibration meter. He currently leads the Particle Counter Division.Kodai YamashitaS&V Measuring Instrument Development Group, Product Development Department, Technical Development Center. Kodai Yamashita is a young successor to devel-opment efforts on various measuring in-struments, such as sound level meters, vibration meters, and analyzers. He is a member of the committee for ISO/TC 108/SC 4 ‘Human exposure to mechani-cal vibration and shock’ in Japan.
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