Crompton precision moving-coil D.C. meter, England. A laboratory or switchboard electrical measuring instrument calibrated 0–15 with markings “0.075 V, 0.015 A, 5 ohms” and provision for external shunt leads (0.05 ohm). Designed for accurate measurement of small direct currents or voltages in electrical testing, calibration benches, and power-station instrumentation panels. Visible movement indicates a sensitive galvanometer-type mechanism. Mid-20th century, c.1930s–1950s.
