Keithley Nanovoltmeter Model 2182A
The two-channel Model 2182A Nanovoltmeter is optimized for making stable, low noise voltage measurements and for characterizing low resistance materials and devices reliably and repeatably. It provides higher measurement speed and significantly better noise performance than alternative low voltage measurement solutions. It offers a simplified delta mode for making resistance measurements in combination with a reversing current source, such as the Model 6220 or 6221.

Features / Benefits
1nV sensitivity / Provides accurate, ultra-low voltage measurements.
Typically just 15nVp-p noise at 1s response time, 40–50nV p-p noise at 60ms / Ensures low noise levels over a wide range of useful response times.
Dual channels / Supports measuring voltage, temperature, or the ratio of an unknown resistance to a reference resistor.
Measurement cycle is synchronized to the power line AC cycle / Minimizes variations due to readings that begin at different phases of the line cycle. The result is exceptionally high immunity to line interference with little or no shielding and filtering required.
Built-in thermocouple linearization and cold junction compensation / Simplifies making accurate temperature measurements.
Internal polarity reversal measurement technique / Eliminates thermal error sources.
Optimized for use with Model 6220/6221 current sources / Allows both instruments to be operated like a single instrument when making differential conductance, pulsed, and resistance measurements.
Delta mode current reversal measurement technique when combined with the 6220 or 6221 / Enables resistance measurements down to 10n?.
2182A/6221 combination synchronizes signal pulses and measurements / Minimizes the amount of power dissipated into a temperature-sensitive DUT.