Graphical Data Recording
Richard J. Smythe · Apress eBooks · 2021
An old Far Eastern proverb advises that “a picture is worth a thousand words.” The truth of the proverb is fully realized in chemical analysis and medical imaging where not only the numerical values but the shape of the recorded data conveys information. Numerous techniques in medical, physical, and many other experimental sciences depend upon the graphical presentation of data. Clinical and chemical analysis has traditionally used chemically sensitive transducers to generate a millivolt signal in response to changing chemical process values. The small signal was amplified electronically and used with a servomotor to mechanically drive a pen across a paper chart to provide a visual record of the chemical process being monitored. Although both x-y and x vs. time plotting systems are extensively employed in the manufacturing process industries, chemical analysis, and other sciences, the electro-mechanical plotting instruments, much like the typewriter, have been replaced by the PC.