Instructions

8845A/8846A
Users Manual
1-12
Input Characteristics
Resolution
Range Resolution
4½ Digits 5½ Digits 6½ Digits
Input Impedance
100 mV 100.0000 mV
10 μV 1 μV
100 nV
10 MΩ or >10 GΩ
[1]
1 V 1.000000 V
100 μV 10 μV 1 μV 10 MΩ or >10 GΩ
[1]
10 V 10.00000 V 1 mV
100 μV 10 μV 10 MΩ or >10 GΩ
[1]
100 V 100.0000 V 10 mV 1 mV
100 μV 10 MΩ ±1%
1000 V 1,000.000 V 100 mV 10 mV 1 mV
10 MΩ ±1%
[1] Inputs beyond ±14 V are clamped through 200 kΩ typical. 10 MΩ is default input impedance.
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
100 mV 0.0025 + 0.003 0.0025 + 0.0035 0.0037 + 0.0035 0.0005 + 0.0005
1 V 0.0018 + 0.0006 0.0018 + 0.0007 0.0025 + 0.0007 0.0005 + 0.0001
10 V 0.0013 + 0.0004 0.0018 + 0.0005 0.0024 + 0.0005 0.0005 + 0.0001
100 V 0.0018 + 0.0006 0.0027 + 0.0006 0.0038 + 0.0006 0.0005 + 0.0001
1000 V 0.0018 + 0.0006 0.0031 + 0.001 0.0041 + 0.001 0.0005 + 0.0001
8845A 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
100 mV 0.003 + 0.003 0.004 + 0.0035 0.005 + 0.0035 0.0005 + 0.0005
1 V 0.002 + 0.0006 0.003 + 0.0007 0.004 + 0.0007 0.0005 + 0.0001
10 V 0.0015 + 0.0004 0.002 + 0.0005 0.0035 + 0.0005 0.0005 + 0.0001
100 V 0.002 + 0.0006 0.0035 + 0.0006 0.0045 + 0.0006 0.0005 + 0.0001
1000 V 0.002 + 0.0006 0.0035 + 0.0010 0.0045 + 0.0010 0.0005 + 0.0001
Additional Errors
Digits NPLC Additional NPLC Noise Error
6½ 100 0 % of range
6½ 10 0 % of range
5½ 1 0.001 % of range
5½ .2
0.0025 % of range +12 μV
4½ 0.02
0.017 % of range +17 μV
AC Voltage Specifications
AC Voltage specifications are for ac sinewave signals >5 % of range. For inputs from 1 % to 5 % of range and <50 kHz,
add an additional error of 0.1 % of range, and for 50 kHz to 100 kHz, add 0.13 % of range.
Maximum Input ....................................................... 750 V rms or 1000 V peak (8845A), 1000 V rms or 1414 V peak
(8846A) or 8 x 10
7
volts-Hertz product (whichever is less) for any
range.
Measurement Method ............................................. AC-coupled true-rms. Measures the ac component of input with up to
1000 V dc bias on any range.
AC Filter Bandwidth:
Slow .................................................................... 3 Hz – 300 kHz
Medium ............................................................... 20 Hz – 300 kHz
Fast..................................................................... 200 Hz – 300 kHz
Common Mode Rejection ....................................... 70 dB at 50 Hz or 60 Hz ±0.1 % (1 kΩ unbalance)
Crest Factor Error (applies to non-sinusoidal waveforms only)
Maximum Crest Factor ....................................... 5:1 at Full Scale