The sampling and analysis can be done at the command of an operator, periodically ( for example, every 15 minutes ), or continuously-providing an analysis result vs . time graph on a chart recorder, computer, or other device.
32.
"' Spark printing "'is an obsolete form of computer printing and before that fax and chart recorder printing which uses a special paper coated with a conductive layer over a contrasting backing, originally black carbon over white paper but later aluminium over black paper.
33.
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.
34.
It enabled sophisticated alarm handling, introduced automatic event logging, removed the need for physical records such as chart recorders, allowed the control racks to be networked and thereby located locally to plant to reduce cabling runs, and provided high level overviews of plant status and production levels.
35.
After graduating from the Stevens Institute of Technology in 1884 with an engineering degree, he returned there in 1886 as an instructor and progressed to become a professor of mathematics in 1899 . While at Stevens, he patented products including a steel lacing for industrial belts and a pressure chart recorder.
36.
Since the 440 Hz tone is only transmitted once per hour, many chart recorders may use this tone to mark off each hour of the day, and likewise, the omission of the 440 Hz tone once per day can be used to mark off each twenty-four-hour period.
37.
The physicist John Taylor wrote that it was likely the measurements shown by the chart recorder used to record the output of the electric current meter in Adam's law offices were fraudulently produced and the explanation for the alleged poltergeist phenomena was a mixture of " expectation, hallucination and trickery ."
38.
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 ).
39.
GFAA spectrometry instruments have the following basic features : 1 . a source of light ( lamp ) that emits resonance line radiation; 2 . an atomization chamber ( graphite tube ) in which the sample is vaporized; 3 . a monochromator for selecting only one of the characteristic wavelengths ( visible or ultraviolet ) of the element of interest; 4 . a detector, generally a photomultiplier tube ( light detectors that are useful in low-intensity applications ), that measures the amount of absorption; 5 . a signal processor-computer system ( strip chart recorder, digital display, meter, or printer ).
