Inventors of the Ammeter


Claude Pouillet This french physicist figured out how to build a tangent galvanometer and understood how it worked. Conservatoire National des Arts et Métiers. Paris, France

Philip Lange This Westinghouse engineer developed galvanometers including circuit controllers, voltmeters and ammeters. Lange’s understanding of electromagnetics in both DC and AC power was cutting edge. He has many patents and worked with Henry M. Byllesby and Oliver Shallenberger. Westinghouse Electric, Pittsburg, PA

Edward Weston He was an early innovator in the electrical industry developing DC systems in the 1870s. His meters are the most well-known brand of electric meters in history. He perfected the permanent magnet moving coil meter and the Weston Cell Battery – the most stable battery to date, his battery was used to calibrate meters since the voltage remains stable over time. Weston Electric Light Company, Newark, NJ

Elihu Thomson developed many types of magnetic coil driven ammeters for use with his complete DC electrical systems in the 1880s. Thomson experimented with AC in 1885 and later developed AC ammeters. He developed the “Thomson Integrating Wattmeter” in 1889. Thomson won an award in 1890 in Paris for this meter. Thomson’s number of patents is only exceeded by Edison, and many of those patents are for electric meters. Meters were something he worked on consistently over the years. General Electric. Lynn, MA

Photo: The Schenectady Museum

William Stanley This great inventor of western Massachusetts was not only a pioneer of early AC power but developer of both magnetic coil driven ammeters and static plate volt/ammeters. He developed phase indicators, static ground detectors, volt meters and other devices to go with this AC system. Eventually he was bought out by General Electric Co. Stanley Electric, Pittsfield, MA

Photo: The Berkshire Museum

Oliver B. Shallenberger – Shallenberger was Westinghouse’s first genius of AC power. In 1888 he developed the Watt-Hour Meter. It is related to the Ammeter in how it works, the difference is that it uses rotating paddles moved by the magnetic current, the rotations are counted. The more power used, the faster the rotations, so therefore we could measure how much power was used in a given amount of time. He also developed a new type of voltmeter. Westinghouse Electric, Pittsburg, PA