Keithley 181 Nanovoltmeter. Unit powers on normally and all range-selection buttons, indicators, and display functions responded during testing.

Testing performed:

• Unit was powered on and allowed to warm up.
• Applied known DC voltages using a Korad laboratory power supply.
• Display responded appropriately to approximately 0.01V, 0.10V, and 1.00V input signals.
• Measured approximately 0.021V with a 0.01V input.
• Measured approximately 0.115V with a 0.10V input.
• Measured approximately 1.008V with a 1.00V input.
• Readings increased proportionally with applied voltage and tracked changes in input level.

Observations:

• Unit continuously exhibits display drift and fluctuation regardless of input condition.
• Similar fluctuation was observed with open inputs, shorted leads, and while measuring applied DC voltages.
• Although the unit responded correctly to changing voltage levels, the displayed value was not completely stable and continuously varied during operation.
• No attempt was made to calibrate, adjust, or repair the instrument.
• Calibration status is unknown.

Includes:

• Keithley 181 Nanovoltmeter only.

Does not include:

• Test leads
• Manual
• Calibration documentation
• Accessories

Plastic case damaged as pictured.

This unit demonstrated functional voltage measurement capability and responded appropriately to applied test voltages; however, due to the continuous display drift/fluctuation and unknown calibration status, buyers should assume calibration, adjustment, troubleshooting, or service may be required depending on their application.