electrolytic polarity indicator
date: label: date made
content: ca 1915
notes: label: Description (Brief)
content: A wooden block in which is set a glass vial containing a liquid (composition unknown) and two platinum electrodes separated by a 1.5" gap. Each electrode is attached to a brass binding post. A bubble is in the vial. The user places a direct current voltage across the unit to determine the polarity of a battery or motor. The mode of operation depends on the liquid. In some units bubbles will form around the negative electrode, in other units the liquid will turn from clear to colored. Reference: William B. Duck catalog, 1915, page 148, for a "New York Polarity Indicator" similar to this unit. Retail price listed at 75 cents. One unit was made for use with batteries, another for use with 50 to 600 volt motors.
label: Location
content: Currently not on view
creditLine: label: Credit Line
content: from Franklin Wingard
dataSource: label: Data Source
content: National Museum of American History
identifier: label: ID Number
content: EM.241556.762
label: accession number
content: 241556
label: catalog number
content: 241556.762
objectType: label: Object Name
content: electrical tester
physicalDescription: label: Measurements
content: overall: 1 1/8 in x 4 in x 3/4 in; 2.8575 cm x 10.16 cm x 1.905 cm