记录仪油墨，红色

Recorder reproduces the output of the electrometer-amplifier or thermal conductivity detector in a graphic form. The differential amplifier compares the input signal from the amplifier-attenuator network with a reference voltage generated in the measuring circuit of the recorder. Error signal, the difference between signals is converted to AC to drive the servo balancing motor. If difference is positive, the motor is driven in one direction and if negative it id driven in opposite direction. The motor is mechanically attached to slidewire and to recorder pen. It may require solid ink.