8845A/8846A
Users Manual
1-14
Resistance
Specifications are for 4-wire resistance function, 2 x 4-wire resistance, or 2-wire resistance with zero. If zero is not used,
add 0.2 Ω for 2-wire resistance plus lead resistance, and add 20 mΩ for 2 x 4-wire resistance function.
Measurement Method ............................................. Current source referenced to LO input
Max. Lead Resistance (4-wire ohms) ..................... 10 % of range per lead for 10 Ω, 100 Ω, 1 kΩ ranges. 1 kΩ per lead on
all other ranges
Input Protection....................................................... 1000 V on all ranges
Common Mode Rejection ............................................140 dB at 50 or 60 Hz ±0.1 % (1 kΩ unbalance)
Normal Mode Rejection .......................................... 60 dB for NPLC of 1 or greater with analog filter off and power line
frequency ±0.1 %
100 dB for NPLC of 1 or greater with analog filter on and power line
frequency ±0.1 %
Analog Filter............................................................ When using the analog filter, specifications are relative to within one
hour of using the ZERO function for that range and NPLC setting.
Input Characteristics
Resolution
Range Resolution
4½ Digits 5½ Digits 6½ Digits
Source Current
10 Ω
[1]
10.00000 Ω 1 mΩ 100 μΩ 10 μΩ
5 mA/13 V
100 Ω 100.0000 Ω 10 mΩ 1 mΩ 100 μΩ
1 mA/6 V
1 kΩ 1.000000 kΩ 100 mΩ 10 mΩ 1 mΩ
1 mA/6 V
10 kΩ 10.00000 kΩ 1 Ω 100 mΩ 10 mΩ 100 μA/6 V
100 kΩ 100.0000 kΩ 10 Ω 1 Ω 100 mΩ 100 μA/13 V
1 MΩ 1.000000 MΩ 100 Ω 10 Ω 1 Ω 10 μA/13 V
10 MΩ 10.00000 MΩ 1 kΩ 100 Ω 10 Ω 1 μA/13 V
100 MΩ 100.0000 MΩ 10 kΩ 1 kΩ 100 Ω 1 μA || 10 MΩ/10 V
1.0 GΩ
[1]
1.000000 GΩ 100 kΩ 10 kΩ 1 kΩ 1 μA || 10 MΩ/10 V
[1] 8846A Only
8846A Accuracy
Accuracy is given as ± (% measurement + % of range)
Range
24 Hour
(23 ±1 °C)
90 Days
(23 ±5 °C)
1 Year
(23 ±5 °C)
Temperature
Coefficient/ °C
Outside 18 to 28 °C
10 Ω 0.003 + 0.01 0.008 + 0.03 0.01+ 0.03 0.0006 + 0.0005
100 Ω 0.003 + 0.003 0.008 + 0.004 0.01 + 0.004 0.0006 + 0.0005
1 kΩ 0.002 + 0.0005 0.008 + 0.001 0.01 + 0.001 0.0006 + 0.0001
10 kΩ 0.002 + 0.0005 0.008 + 0.001 0.01 + 0.001 0.0006 + 0.0001
100 kΩ 0.002 + 0.0005 0.008 + 0.001 0.01 + 0.001 0.0006 + 0.0001
1 MΩ 0.002 + 0.001 0.008 + 0.001 0.01 + 0.001 0.001 + 0.0002
10 MΩ 0.015 + 0.001 0.02 + 0.001 0.04 + 0.001 0.003 + 0.0004
100 MΩ 0.3 + 0.01 0.8 + 0.01 0.8 + 0.01 0.15 + 0.0002
1 GΩ 1.0 + 0.01 1.5 + 0.01 2.0 + 0.01 0.6 + 0.0002