Editing Chart recorder (section)

==Origins==

[[Charles Babbage]] incorporated a chart recorder into the [[dynamometer car]] that he built in 1838 or 1839.<ref>{{cite book |authorlink=Charles Babbage |title=Passages from the life of a philosopher |publisher=Longman, Green, Longman, Roberts and Green |chapter=XXV. Railways |publication-date=1864 |pages=328–334 |chapter-url=https://archive.org/stream/passagesfromlif00babbgoog#page/n334/mode/1up}}</ref> 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 mechanism advancing the paper.<ref>Samuel F. B. Morse, Improvement in the Mode of Communicating Information by Signals by the Application of Electro-Magnetism, [https://patents.google.com/patent/US1647 U.S. Patent 1647], June 20, 1840; see page 4 column 2</ref> In 1848-1850 a system of such registers was used by [[John Locke (naturalist)|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. <ref>Richard Stachurski ''Longitude by Wire: Finding North America'' Univ of South Carolina Press, 2009 {{ISBN|1570038015}} pages 101-103 </ref> [[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 register]]s, 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.<ref>{{cite web |author=Bristol, William H. |title=Pressure Indicator and Recorder, U.S. Patent 389,635 issued Sep 18, 1888 |url=https://patents.google.com/patent/US389635 |access-date=2008-05-25 }}</ref> 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.<ref>{{cite web |author=Stevens, John Cyprian |title=Water Stage Recorder, U.S. Patent 1,163,279 issued Dec 7, 1915 |url=https://patents.google.com/patent/US1163279 |access-date=2008-03-20 }}</ref> 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.