Multichannel pen recorder for electrical logging operations
J. D. Eisler, David Silverman · Geophysics · 1947
Abstract Principle of operation, constructional details and performance of a servo-mechanism type pen recorder are described. The recorder comprises two independent channels of servo-amplifier and motor, each capable of moving an inking pen in a rectilinear fashion across a chart moving proportionally to the bore hole depth traversed by an electrode array. The speed and resolution of the recorder is more than adequate for electrical logging requirements. The recorder is capable of recording both d.-c. and a.-c. signals.