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8508A
Service Manual
1-16
Resistance - Normal Mode (Secondary Specifications)
[1] [2] [3] [10]
Temperature Coefficient
15 °C - 30 °C
5 °C - 15 °C
30 °C - 40 °C
Range Measurement
Current
Transfer Uncertainty
20 mins ±1 °C
± (ppm Reading
+ ppm Range)
± ppm Reading/°C
2
Ω
100 mA
2.0 + 2.0
1.5
2.5
20
Ω
10 mA
0.8 + 0.7
0.6
1.0
200
Ω
10 mA
0.2 + 0.15
0.5
0.8
2 k
Ω
1 mA
0.2 + 0.15
0.5
0.8
20 k
Ω
100
μ
A
0.2 + 0.15
0.5
0.8
200 k
Ω
100
μ
A
0.2 + 0.15
0.5
0.8
2 M
Ω
10
μ
A
0.5 + 0.5
0.6
1.0
20 M
Ω
1
μ
A
2.5 + 5
2
3
200 M
Ω
100 nA
15 + 50
20
30
2 G
Ω
10 nA
200 + 500
200
300
Resistance - Lo Current Mode (Secondary Specifications)
[1] [2] [3] [10]
Temperature Coefficient
15 °C - 30 °C
5 °C - 15 °C
30 °C - 40 °C
Range Measurement
Current
Transfer Uncertainty
20 mins ±1 °C
± (ppm Reading
+ ppm Range)
± ppm Reading/°C
2
Ω
100 mA
2.0 + 2.0
1.5
2.5
20
Ω
10 mA
0.8 + 0.7
0.6
1.0
200
Ω
1 mA
0.8 + 0.7
0.6
1.0
2 k
Ω
100
μ
A
0.8 + 0.7
0.6
1.0
20 k
Ω
10
μ
A
0.8 + 0.7
0.6
1.0
200 k
Ω
10
μ
A
0.5 + 0.5
0.6
1.0
2 M
Ω
1
μ
A
2.0 + 0.5
2
3
20 M
Ω
100 nA
15 + 5
20
30
200 M
Ω
10 nA
200 + 500
200
300
2 G
Ω
10 nA
200 + 500
200
300
Resistance - High Voltage Mode (Secondary Specifications)
[1] [2] [3]
Temperature Coefficient
15 °C - 30 °C
5 °C - 15 °C
30 °C - 40 °C
Range
[9]
Measurement
Current
Transfer Uncertainty
20 mins ±1 °C
± (ppm Reading
+ ppm Range)
± ppm Reading/°C
20 M
Ω
10
μ
A
0.5 + 0.5
0.6
1.0
200 M
Ω
1
μ
A
2.0 + 0.5
2.0
3
2 G
Ω
100 nA
15 + 50
20
30
20 G
Ω
10 nA
200 + 500
200
300
Type
........................................................................ True 4-wire with Ohms guard. 2-wire selectable.
Max Lead Resistance
............................................ 10
Ω
in any or all leads, 1
Ω
on 2
Ω
range
Full Scale Measurement Voltage
Normal Mode .......................................................... 200 mV/2 V/20 V
Lo Current Mode ..................................................... 200 mV/2 V
High Voltage Mode ................................................. 200 V
Protection
(All ranges) .......................................... 250 V rms, 360 V pk
Ratio Accuracy
Range to Range...................................................... ±(Net Front Input Ac Net Rear Input Accuracy)
Within Range .......................................................... Apply 24 hour or 20 minute Transfer Uncertainty specifications
Settling Time
......................................................... Up to 200 k
Ω
range generally the same as DC Voltage Filter In but
depends on external connections
Summary of Contents for 8508A
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Page 8: ...8508A Service Manual vi ...
Page 10: ...8508A Service Manual viii ...
Page 12: ...8508A Service Manual 1 2 ...
Page 32: ...8508A Service Manual 1 22 ...
Page 34: ...8508A Service Manual 2 2 ...
Page 40: ...8508A Service Manual 2 8 ...
Page 84: ...8508A Service Manual 3 44 ...
Page 88: ...8508A Service Manual 4 2 ...
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