The Keysight (Agilent/HP) 34420A is a high-performance 7 1/2-digit nanoVolt/micro-Ohm meter engineered for highly sensitive, low-level measurements. Delivering exceptional noise performance of 1.3 nVrms / 8 nVpp and extremely fine resolution down to 100 pV and 100 nOhm, it is optimized for demanding metrology, dry circuit testing, and high-precision temperature measurements using direct SPRT, RTD, thermistor, and thermocouple sensors.

Specifications

General

ParameterValue
InterfacesRS-232, GPIB
Display7 1/2 Digits
Included Input CableKeysight 34102A Low-Thermal Input Cable

Physical

ParameterValue
Power Supply100V / 120V / 220V / 240V ±10%, 45-66 Hz and 360-440 Hz, 25 VA max
Operating Temperature0 to 55
Dimensions (W×H×D)254.4 × 103.6 × 374 (with bumpers) / 212.8 × 88.5 × 348.3 (without bumpers)

Measurement Characteristics

ParameterValue
Resolution (Digits)7 1/2 digits
Measurement ModesDC Voltage, Resistance, Temperature

DC Voltage Specifications

ParameterValue
Maximum Resolution100 pV
RMS Noise1.3 nVrms
Peak-to-Peak Noise8 nVpp
Accuracy (24-Hour)2 ppm (basic DCV)

Resistance Specifications

ParameterValue
Measurement Configuration3 built-in resistance functions (including low power, dry circuit testing)
Dry Circuit Test Voltage Limit20 mV
Maximum Test Current (Resistance)10 mA (on 1 Ω range)
Offset-Compensated OhmsSupported (removes thermal EMF errors)

Temperature Specifications

ParameterValue
Supported Sensor TypesSPRT, RTD, Thermistor, Thermocouple
Supported Thermocouple TypesB, E, J, K, N, R, S, T

Math and Filtering

ParameterValue
Math FunctionsScaling, Statistics
FilteringSelectable analog and digital filtering
Analog OutputChart recorder analog output

Input / Output and Connectivity

ParameterValue
Input TerminalsShielded, copper pin connector
Built-in ScannersBuilt-in low noise 2-channel scanners
Command Language CompatibilitySCPI, Keithley 181

Measurement Capabilities

ParameterValue
Voltage Ranges1 mV to 100 V
Resistance Ranges1 Ω to 1 MΩ

Inputs & Protection

ParameterValue
Input Resistance (1 mV to 10 V ranges)> 10 GΩ
Input Resistance (100 V range)10 MΩ ± 1%
Maximum Input Voltage150 V peak to any terminal

Performance

ParameterValue
Maximum Reading Rate250 readings/second (at 4.5 digits)
Integration Times (NPLC)0.02, 0.2, 1, 10, 100, 200 NPLC
Common Mode Rejection Ratio (CMRR)140 dB (DC, 1 kΩ unbalance)
Normal Mode Rejection Ratio (NMRR)60 dB (at 50/60 Hz ±0.1%, ≥1 NPLC)

Environmental

ParameterValue
Storage Temperature-40°C to 75°C
Operating Humidity< 95% RH up to 40°C

Inputs

ParameterValue
Input Channels2 (CH1 and CH2) with built-in low-thermal scanner

Technology

Digital Multimeter (DMM) / Nanovoltmeter

Applications

Low-level voltage measurement, precision resistance testing, dry circuit testing, thermometry (SPRT, RTD, Thermocouple)