What is a recorder?

Recorder

Basically the recorder is a common auxiliary device and is used to graph the process variable. Recorders usually have indicators built into them to show the instantaneous value of the instrument signal along with historical values, and for this reason are commonly designated recorder indicators.

Circular chart recorder

A circular chart recorder uses a round sheet of paper, moving slowly under the pen and moving sideways by a servomechanism driven by an instrument signal.

Bar chart recorder

A strip chart recorder uses a scroll of paper drawn gently behind one or more side-moving pens, while a paperless recorder eliminates paper entirely by plotting graphic trend lines on a computer screen. Recorders are extremely useful for troubleshooting process control problems. This is especially true when the recorder is configured to record not only the process variable but also the setpoint and output variables of the controller.