Model 2182A Nanovoltmeter
The model 2182A nanovoltmeter is optimized for making low
noise measurements in research, metrology, nanotechnology, superconductivity,
and other low voltage/resistance applications.
The Model 2182A brings a powerful new set of capabilities to researchers
when used in conjunction with Keithley's recently introduced model 6221 AC/DC
current source; users now are able to make resistance measurements, pulsed I-V
measurements, and differential conductance measurements faster and more accurately
than previously possible, in many cases eliminating the need for an expensive
lock-in amplifier or AC resistance bridge. The combination is also useful in
many nanotechnology applications because of its ability to measure resistance
while dissipating very little power in the device under test (DUT).
The Model 2182A is able to minimize DC drift and noise common to low voltage
measurements with rapid measurement speeds beyond what is achievable by
previous nanovoltmeters or sensitive DMMs. The instrument is able to make 15nV
peak-to-peak measurements at one-second response times and 40-50 nV p-p
measurements at 60 millisecond times.
The unit features a built-in Delta Mode to coordinate measurements with a
reversing current source (one-button operation when used with Keithley model
6221) at up to 24Hz with 3nVrms/root-Hz noise, creating a system optimized for
precision measurements of low resistance materials or devices. The new delta
mode operation alternates nearly three times faster than its predecessor model,
reducing measurement noise by nearly a factor of two. In addition, the new
delta mode incorporates a new cancellation method that reduces the effects due
to changing thermoelectric voltages by a factor of ten compared to its
predecessor.
By synchronizing to line frequency, the Model 2182A provides 110dB rejection
to noise at line frequency and minimizes the effect of AC common-mode currents.
The unit offers two channels for measuring voltage or temperature. Or, the
second channel can be used for reading the ratio of an unknown resistance
directly to a reference resistor. Built-in thermocouple calculations for types
J, K, N, T, E, R, S, and B are provided.
Integrating the Model 2182A with Keithley s new current source, model 6221,
creates a powerful test system capable of acting as a single instrument. When
linked with the Ethernet-enabled Model 6221, the combined system effectively
operates as an Internet-controlled nanovoltmeter system, allowing customers to
control both sourcing and measuring through a single Internet IP address.
Some of the most important capabilities of the Model 2182A, when combined
with the model 6221, include:
* Wide measurement range, from 10 nano-ohms (lowest noise) to 1 Gohms.
* Differential conductance, an increasingly common measurement for
characterizing semiconductor and nanotechnology materials, can be performed 10X
faster and with lower noise by the Models 6221 and 2182A than by existing
solutions, including lock-in amplifiers and AC resistance bridges.
* When combined with the Model 6221, the Model 2182A can support pulsed
resistance and pulsed I-V measurements with pulses as short as 50 microseconds,
even at low currents. Short pulses mean less power put into the DUT,
particularly important in very small devices where even a small amount of power
may be enough to destroy the device or produce an invalid reading. To eliminate
DC offsets and line frequency noise in these sensitive pulse measurements, the
6221/2182A pulsed mode utilizes both line synchronization and delta-mode
techniques.
Key Features and Benefits:
- Make low noise measurements
at high speeds, typically just 15nV p-p noise at 1s response time, 40-50nV
p-p noise at 60ms - Delta mode coordinates
measurements with a reversing current source at up to 24Hz with 30nV p-p
noise (typical) for one reading. Averages multiple readings for greater
noise reduction - Synchronization to line
provides 110dB NMRR and minimizes the effect of AC common-mode currents - Dual channels support
measuring voltage, temperature, or the ratio of an unknown resistance to a
reference resistor - Built-in thermocouple
linearization and cold junction compensation
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.
Related Applications:
- Research
- - Determining the transition temperature
of superconductive materials - - I-V characterization of a
material at a specific temperature - - Calorimetry
- - Metrology
- - Intercomparisons of
standard cells - - Null meter for resistance
bridge measurements
