The Eppley Standard Cell

Electrical instruments are calibrated using a very accurate standard cell that generates exactly one volt. The United States relied on obtaining standard cells from Germany until World War I, when Eppley Laboratories of Newport, Rhode Island, developed a cadmium sulfide cell that produced a very steady and accurate one volt. The quality and accuracy of this device released the U.S. from dependence on foreign sources for standard cells.

Eppley Laboratories prospered and developed many other products. When the company decided to close the standard cell division, Museum volunteer Paul Weigold convinced the lab to turn over their complete operation to the museum, including records containing important test information about each cell manufactured.

Anyone interested in receiving a copy of the test information for the cell they possess can contact museum director John Ellsworth at

Be sure to include your name, mailing address and – most important – the serial number of the cell. There is a $5.00 fee for a copy of the record.

 Special Displays