Maker's Name: 
C. I. Co Ltd.
10 × 10 × 8 cm

This electrometer is a version of the quadrant electrometer. Parallel vertical plates, separated by 6mm, are used as quadrants, with a silvered glass fibre pointer mounted on a horizontal taut quartz suspension, so it rotates about a horizontal axis.

As the iinstrument is small enough, it may be mounted on a microscope stage, and the needle deflection observed. Currents of the order of 10^-15 Amp can be detected.

This instrument was designed for portability and insensitivity to changes in level.