Keithley 177 Microvolt DMM Digital Multimeter Analog Output For Parts

Keithley 177 Microvolt DMM Digital Multimeter Analog Output For Parts

The Keithley 177 Microvolt DMM is a 4.5-digit benchtop digital multimeter capable of measuring DC voltage, AC voltage, DC current, AC current, and resistance. It features a rear-panel analog output (2V full scale) for connection to recorders or other instruments. This unit powers on and the LED display illuminates, but the readings are not accurate and the display eventually reverts to blinking zeros. It is being sold strictly AS-IS for parts or repair and is not in working condition.

Specifications & What's Included

• Make / Model: Keithley 177 Microvolt DMM
• Display: 4.5-digit red LED
• Measurement functions: DCV, ACV, DCA, ACA, Resistance (Ohms)
• DCV ranges: 200mV, 2V, 20V, 200V, 1200V (1200V momentary max input)
• ACV ranges: 2V, 20V, 200V, 1000V RMS max
• DCA ranges: 200µA, 2mA, 20mA, 200mA, 2A
• ACA ranges: 2mA, 20mA, 200mA, 2500mA
• Resistance ranges: 200Ω, 2kΩ, 20kΩ, 200kΩ, 2MΩ, 20MΩ
• Input impedance: 10MΩ (DCV), 1MΩ / 75pF (ACV)
• Analog output: rear panel, 2V full scale, 5kΩ output impedance
• Internal fuses: Line 1/8A 3AG Slow; Current 2A 3AG Normal
• Power: 105–125V or 210–250V, 50–60Hz AC, 15VA max
• Power connector: NEMA L6-30 locking plug (30A, 250V) on attached brown cord
• Serial Number: 25931 (rear panel)
• Includes: Unit with attached power cord only — no test leads
• Condition: For parts or repair — not working (see condition block below)

Applications

The Keithley 177 was introduced in the late 1970s as a high-sensitivity benchtop DMM aimed at laboratory and metrology applications requiring microvolt-level DC voltage resolution. It belongs to Keithley's early line of precision DMMs and was commonly used in calibration labs, standards labs, and R&D environments where low-level signal measurement and analog chart-recorder output were needed. The rear-panel analog output allowed the 177 to drive strip-chart recorders for continuous signal logging — a common setup before digital data acquisition systems became standard. Today these instruments are sought by technicians and hobbyists for bench repair, calibration study, or as a source of precision-grade components and subassemblies. A unit in this as-is condition is best suited for someone with the technical skill to diagnose and repair DMM circuitry, or as a parts source for a working Keithley 177.