Chart recorder
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A chart recorder is an electromechanical device that records an electrical or mechanical input trend onto a piece of paper. Chart recorders may record several inputs using different color pens and may
A section of circular chart recorder paper
Chart recorders of a control panel at a water purification plant record water flow rates at different stages of the process.
A circular chart recorder tracking temperature in a building
Galvanometer
Videos
A galvanometer is an electromechanical measuring instrument for electric current. Early galvanometers were uncalibrated, but improved versions, called ammeters, were calibrated and could measure the f
Chart recorder
…spark that makes a visible spot on aluminized paper. One form of sensitive and high-speed recorder used beams of ultraviolet light reflected off mirror galvanometers, directed at light-sensitive paper. The earliest instruments derived power to move the pen directly from the sensed process signal, which limited their…
An early D'Arsonval galvanometer showing magnet and rotating coil
Close-up view (rear) of a permanent magnet type moving coil meter
Closed-loop galvanometer-driven laser scanning mirror
A galvanometer mechanism (center part), used in an automatic exposure unit of an 8 mm film camera, together with a photoresistor (seen in the hole on top of the leftpart).