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A chart recorder is an electromechanical device that records an electrical or mechanical input trend onto a piece of paper (the chart). Chart recorders may record several inputs using different color pens and may record onto strip charts or circular charts. Chart recorders may be entirely mechanical with clockwork mechanisms, electro-mechanical with an electrical clockwork mechanism for driving the chart (with mechanical or pressure inputs), or entirely electronic with no mechanical components at all (a virtual chart recorder). Chart recorders are built in three primary formats. Strip chart recorders have a long strip of paper that is ejected out of the recorder. Circular chart recorders have a rotating disc of paper that must be replaced more often, but are more compact and amenable to being enclosed behind glass. Roll chart recorders are similar to strip chart recorders except that the recorded data is stored on a round roll, and the unit is usually fully enclosed. Chart recorders pre-dated electronic data loggers which have replaced them in many applications. ==Origins== Charles Babbage incorporated a chart recorder into the dynamometer car that he built in 1838 or 1839. Here is how he described it: "A roll of paper a thousand feet in length was slowly unwinding itself upon the long table ... About a dozen pens connected with a bridge crossing the middle of the table were each marking its own independent curve gradually or by jumps ..." The paper advance was geared to the wheels of the railroad carriage, while pens recorded time, the drawbar pull of the locomotive, and numerous other variables. Part of Samuel Morse's telegraph system was an automatic recorder of the dots and dashes of the code, inscribed on a paper tape by a pen moved by an electromagnet, with a clockwork mehanism advancing the paper.〔Samuel F. B. Morse, Improvement in the Mode of Communicating Information by Signals by the Application of Electro-Magnetism, (U.S. Patent 1647 ), June 20, 1840; see page 4 column 2〕 In 1848-1850 a system of such registers was used by John Locke to improve the precision of astronomical observations of stars, providing timing precision much greater than previous methods. This method was adopted by astronomers in other countries as well. 〔Richard Stachurski ''Longitude by Wire: Finding North America'' Univ of South Carolina Press, 2009 ISBN 1570038015 pages 101-103 〕 William Thomson, 1st Baron Kelvin's syphon recorder of 1858 was a sensitive instrument that provided a permanent record of telegraph signals through long underwater telegraph cables. These recorders came to be referred to as pen registers, although this term later became part of law enforcement jargon referring to the use of such a register to record dialed telephone numbers. A patent for a 'Pressure Indicator and Recorder' was issued to William Henry Bristol, on September 18, 1888.〔(【引用サイトリンク】title=Pressure Indicator and Recorder, U.S. Patent 389,635 issued Sep 18, 1888 )〕 Bristol went on to form the Bristol Manufacturing Company in 1889. The Bristol Company was acquired by Emerson Electric Company in March 2006, and continues to manufacture a number of different electro-mechanical chart recorders, as well as other instrumentation, measurement, and control products. The first chart recorder for environmental monitoring was designed by American inventor J.C. Stevens while working for Leupold & Stevens in Portland, Oregon and was issued a patent for this design in 1915.〔(【引用サイトリンク】title=Water Stage Recorder, U.S. Patent 1,163,279 issued Dec 7, 1915 )〕 Chart recorders are still used in applications where instant visual feedback is required or where users do not have the need, opportunity or technical ability to download and view data on a computer or where no electrical power is available (such as in hazardous zones on an oil rig or in remote ecological studies). However, dataloggers' decreasing cost and power requirements allow them to increasingly replace chart recorders, even in situations where battery power is the only option. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Chart recorder」の詳細全文を読む スポンサード リンク
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