Make
Westinghouse
Model
35121
Year
~1906~
Overview
The Westinghouse 35121 is a portable analog ammeter designed for measuring electrical current in field, laboratory, and industrial applications. Built for durability and accuracy, it was intended for technicians working on power systems, electrical equipment, and maintenance tasks.
Technical Specifications
| Category | Details |
|---|---|
| Manufacturer | Westinghouse Electric Corporation |
| Model | 35121 |
| Product Type | Portable ammeter |
| Measurement | Electrical current (amperes) |
| Display Type | Analog needle indicator |
| Measurement Type | AC and/or DC (depends on specific unit configuration) |
| Range | Model-dependent (commonly multiple ranges via selector or terminals) |
| Accuracy | Typically within a few percent (varies by range and condition) |
| Input Method | Direct connection or external shunt (for higher currents) |
| Construction | Portable case, metal housing, glass-covered dial |
Physical Description
The 35121 portable ammeter is housed in a rugged case suitable for field use. The front panel includes a clearly marked ampere scale with a needle pointer for real-time readings. Some units may include multiple binding posts or terminals to support different current ranges or external shunts.
The enclosure is typically metal or heavy-duty composite, with a handle or protective cover depending on configuration. The design emphasizes portability, mechanical stability, and ease of reading under varying conditions.
History
Portable ammeters like the Westinghouse 35121 were widely used during the early to mid-20th century, particularly before digital instruments became common. They were essential tools for electricians, engineers, and maintenance personnel working with generators, motors, and distribution systems.
Westinghouse produced a broad range of portable test instruments to complement its electrical infrastructure products. The 35121 reflects this era of robust, field-oriented instrumentation designed for reliability and long service life.