Measurement Characteristics - Agilent Technologies 34420A User Manual

DC Voltage Noise Specifications *
Observation Period
2-Minute
RMS
Range Noise
1 mV 1.3 nV
RMS
10 mV 1.5 nV
RMS
100 mV 10 nV
RMS
1 V 100 nV
RMS
10 V 450 nV
RMS
100 V 11 V
RMS
* After a 2-hour warm-up, ± 1°C, 6.5 digits (10 PLC) with Analog
Filter Off and Digital Filter Medium (50 reading average). 2-Minute
RMS and 24-hour noise typical. For measurements using 0.02 or
0.2 NPLC, add 800 nV RMS noise.
DC Voltage Noise vs Source Resistance *
Source
Noise
Resistance
0 1.3 nV
RMS
100 1.7 nV
RMS
1k 4 nV
RMS
10k 13 nV
RMS
100k 41 nV
RMS
1M 90 nV
RMS
* Typical noise behavior for Ch 1 or Ch 2, after 2 hour warm-up,
6.5 digits (10 PLC), 2 minute observation period on 1 mV range.
For peak-to-peak noise, multiply RMS noise by 6.
Chapter 8 Specifications
34420A Nano Volt/Micro Ohm Meter
2-Minute 24-Hour
Peak-Peak Peak-Peak
Noise Noise
8 nVpp 12 nVpp
10 nVpp 14 nVpp
65 nVpp 80 nVpp
650 nVpp 800 nVpp
3 Vpp 3.7 Vpp
75 Vpp 90 Vpp
Analog Filter Digital Filter
Off Med
Off Med
Off Med
Off Med
On Med
On Slow

MEASUREMENT CHARACTERISTICS

DC Voltage
Measurement Method Continuously Integrating
Multi-slope III A-D Converter
A-D Linearity 0.00008% of reading + 0.00005% of range
Input Resistance
100V (Ch1 only) 10 M ± 1%
1mV through 10V
>10 G , in parallel with <3.6 nF
Input Bias Current
<50 pA at 25°C
Injected Current* <50 nA pp at 50 or 60 Hz
Input Protection 150 V peak any input terminal to
Channel 1 LO, continuous
Channel Isolation Isolation between input channels
>10
Earth Isolation 350 V peak any input terminal to
earth. Impedence from any input
terminal to earth is
>10 G and < 400 pF
Maximum Voltage Channel 1 LO to Channel 2 LO,
150V peak
Resistance
Measurement Method Selectable 4-wire or 2-wire ohms.
Current Source referenced to
Channel 1 LO input
Offset Compensation Used on all ranges except
100 k and 1 M .
Can be turned off if desired
Protection 150V peak
Open Circuit Voltage For Resistance and Low Power
Resistance <14 V. 20 mV, 100 mV,
500 mV selectable clamp
* Injected current is calibrated at the factory. Different line power
configurations will require recalibration.
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