Establishments primarily engaged in manufacturing instruments for measuring the characteristics of electricity and electrical signals, such as voltmeters, ammeters, wattmeters, watt-hour meters, demand meters, and equipment for testing the electrical characteristics of electrical, radio, and communication circuits and of internal combustion engines. Establishments primarily engaged in the manufacturing of electronic checkout, monitoring, evaluating, and other electronic support equipment for electronic navigational, radar, and sonar systems are classified in Industry 3812, and those manufacturing similar equipment for communications systems classified in Industry Group 366.

• Alternator and generator testers
• Ammeters
• Ampere-hour meters
• Analog-to-digital converters, electronic instrumentation type
• Analyzers for testing electrical characteristics
• Audiometers, except medical
• Automotive ammeters and voltmeters
• Battery testers, electrical
• Bleed control cabinets (engine testers)
• Bridges, electrical: e.g., Kelvin, Wheatstone, vacuum tube, and
• Current measuring equipment
• Decade boxes: capacitance, inductance, and resistance
• Demand meters, electric
• Digital panel meters, electricity measuring
• Digital test equipment, electronic and electrical circuits and equipment
• Digital-to-analog converters, electronic instrumentation, type
• Diode and transistor testers
• Distortion meters and analyzers
• Elapsed time meters, electronic
• Electron tube test equipment
• Electronic test equipment for testing electrical characteristics
• Energy measuring equipment, electrical
• Field strength and intensity measuring equipment, electrical
• Frequency meters: electrical, mechanical, and electronic
• Frequency synthesizers
• Function generators
• Galvanometers, except geophysical
• Ignition testing instruments
• Impedance measuring equipment
• Indicating instruments, electric
• Instrument relays, all types
• Instrument shunts
• Instruments for measuring electrical quantities
• Instruments, electric: for testing electrical characteristics
• Integrated-circuit testers
• Integrating electricity meters
• Internal combustion engine analyzers, to test electrical characteristics
• Laboratory standards, electric: resistance, inductance, and capacitance
• Logic circuit testers
• Measuring equipment for electronic and electrical circuits and
• Measuring instruments and meters, electric
• Meters, electric: pocket, portable, panelboard, and graphic recording
• Meters, power factor and phase angle
• Microwave test equipment
• Multimeters
• Network analyzers
• Ohmmeters
• Oscillators, audio frequency and radio frequency (instrument types)
• Oscillographs and oscilloscopes
• Potentiometric instruments, except industrial process type
• Power measuring equipment, electrical
• Pulse (signal) generators
• Radar testing instruments, electric
• Radio apparatus analyzers for testing electrical characteristics
• Radio set analyzers, electrical
• Radio tube checkers, electrical
• Radio frequency measuring equipment
• Recorders, oscillographic
• Reflectometers, sliding shorts
• Resistance measuring equipment
• Semiconductor test equipment
• Signal generators and averages
• Spark plug testing instruments, electric
• Spectrum analyzers
• Standard cells
• Standards and calibration equipment for electrical measuring, except
• Standing wave ratio measuring equipment
• Stroboscopes
• Sweep generators
• Sweep oscillators
• Synchroscopes
• Tachometer generators
• Test equipment for electronic and electrical circuits and equipment
• Test sets, ignition harness
• Time code generators
• Transformers, instrument: portable
• Tube testers
• Volt-ohm milliammeters
• Voltmeters
• Watt-hour and demand meters, combined
• Watt-hour and time switch meters, combined
• Watt-hour meters, electric
• Wattmeters
• Waveform measuring and/or analyzing equipment