An ac Operated Portable Electrometer‐Type Millivoltmeter

摘要

A stable line‐powered dc millivoltmeter is described which combines the advantages of a directly calibrated scale with the long‐range accuracy of a precision potentiometer. Fractional millimicroampere current drain and a full‐range scale of ±1 volt with 1‐millivolt sensitivity at all settings makes the instrument unusually useful for biophysical, electrochemical, and physical measurements.