RTJ_vol1_EN
9/24

Initiating Development of Sound Level Metersin Response to the Growing Problem of Noise PollutionSeven typical pollution problems that pose issues for the national, as well as municipal governments, are air pollution, water pollution, soil contam-ination, noise, vibration, land subsidence, and oensive odors. Of these, noise is the most serious in terms of the number of complaints received and the levels of sensory and psychological stress involved. The number of complaints received concerning noise has remained mostly constant or risen over the past 20 years.In Japan, Rion introduced its rst sound level meter in 1955. This was during the post-war recovery, a time when noise from factories, construc-tion sites, and public transportation systems was emerging as a major social issue, mainly in urban areas.“Outside Japan, New York City was already facing the problem of noise generated by construction work, cars, and elevated railways in the 1920s. By 1930, people were taking noise measurements. In 1953, Koji Sato, one of the founders of the Kobayasi Institute of Physical Research (Rion’s pre-decessor) and our fourth president and CEO, attended the 1st Interna-tional Congress on Acoustics as a representative of Japan. During his trip, he acquired a sound level meter in the United States to launch a develop-ment project, and that was the start of the sound level meter business at Rion.”At that time, Rion had been producing sensors for microphones and ear-phones as well as hearing aids and other acoustic products. The technolo-gies for these products and the results of research at the Kobayasi Institute of Physical Research were applied to create the N-1101, an indicating sound level meter, which oered a measurement range of 45–130 phons. The model was received well and entered wide use in noise countermeasures and occupational health measures by cities and researchers in noise-re-lated elds. Since then, Rion has worked with governmental agencies like the Environmental Pollution Research Institute of the Tokyo Metropolitan Government and the Kobayasi Institute of Physical Research to develop and provide more sophisticated sound measuring instruments.As Japan entered its period of rapid economic growth in the 1960s, this led to further aggravation of the problem of environmental pollution throughout the country, which in turn led to the promulgation of the Basic Act for Environmental Pollution Control in 1967, the Noise Regula-tion Act in 1968, and JIS C 1502 in 1970. These regulations dramatically increased the demand for sound level meters among municipalities and businesses.Initially, Rion was required only to obtain permits to manufacture sound level meters, specied as measuring instruments in the Measurement Act. Then, as a result of government inspections becoming mandatory in 1973, Rion’s NA-09 became the rst sound level meter in Japan to win government approval. The popularity of this model grew explosively for use in measuring noise pollution, which had become even more serious. Around that time, needs began to emerge for recording and analyzing functions that would help in devising practical noise countermeasures, to which Rion responded with various technological innovations.In the 1970s, the pollution problem was at its peak, and related measure-ments were being made throughout Japan. Rion’s street noise digital dis-play system helped raise public awareness of noise regulations. The rst units were placed in front of Shibuya Station and at a Nishi Ginza inter-section in Tokyo. We changed the public perception of the problem by allowing people to view noise levels on a large digital display board.From Maker of Sound Level Meters to Maker of Acoustic Measuring InstrumentsIn 1978, Rion produced the NA-20 sound level meter. In addition to the requirements of the JIS and the Measurement Act, this met the standards of international IEC standards. This model became the base model for the development of future sound level meters.At the time, Rion had established itself as a manufacturer of sound level meters. But it was yet to provide precision systems that would elevate [N-1101] (1955)The N-1101 was Rion’s rst sound level meter and the rst compact sound level meter made in Japan. The measure-ment range was 45–130 phons. The model was widely used in noise countermeasures by city governments and in occupa-tional health measures.[NA-07] (1964)The NA-07 was a portable in-dicating sound level meter. Cutting-edge designs were adopte d for the microphone attachment, the calibration de-vice, and the handle. The out-put terminal was isolated from the circuitry for the sound level measurement, allowing users to perform analysis and recording while viewing the meter.[NA-09] (1974)This model became the rst in Japan to receive S-1 type approv-al as an ordinary sound level me-ter. Equipped with a condenser microphone, the popularity of the NA-09 grew explosively as an instrument for measuring noise pollution which had become an increasingly pressing problem.[NA-20] (1978)Development of the NA-20 was based on painstaking attention to detail. It took three years, from conception to release of the product. The model met interna-tional IEC standards, in addition to the requirements of the JIS and the Measurement Act.7

元のページ  ../index.html#9

このブックを見る