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Model 6485 Picoammeter Instruction Manual
Range, Units, Digits, Rate, and Filters
4-5
Rate
The RATE key selects the integration time of the A/D converter. This is the period of time
the input signal is measured. The integration time affects the amount of reading noise, as
well as the ultimate reading rate of the instrument. The integration time is specified in
parameters based on a number of power line cycles (NPLC), where 1 PLC for 60Hz is
16.67msec (1/60) and 1 PLC for 50Hz (and 400Hz) is 20msec (1/50).
In general, Model 6485 has a parabola-like shape for its speed vs. noise characteristics and
is shown in
. Model 6485 is optimized for the 1 PLC to 10 PLC reading rate. At
these speeds (lowest noise region in the graph), Model 6485 will make corrections for its
own internal drift and still be fast enough to settle a step response <100ms.
Figure 4-1
Speed vs. noise characteristics
Table 4-3
Ranges and values
Range
<n> value
Display (5
-
digit
resolution)
DDC
20mA
2mA
200
µ
A
20
µ
A
2
µ
A
200nA
20nA
2nA
2E-2 or 0.02
2E-3 or 0.002
2E-4 or 0.0002
2E-5 or 0.00002
2E-6 or 0.000002
2E-7 or 0.0000002
2E-8 or 0.00000002
2E-9 or 0.000000002
00.0000 mA
0.00000 mA
000.000
µ
A
00.0000
µ
A
0.00000
µ
A
000.000
n
A
00.0000
n
A
0.00000
n
A
R8
R7
R6
R5
R4
R3
R2
R1
Lowest
noise
region
Voltage
Noise
166.7
µ
s
16.67ms
166.67ms
Integration Time
Содержание 6485
Страница 1: ...Model 6485Picoammeter Instruction Manual A G R E A T E R M E A S U R E O F C O N F I D E N C E ...
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Страница 44: ...1 20 Getting Started Model 6485 Picoammeter Instruction Manual ...
Страница 66: ...3 6 Measurements Model 6485 Picoammeter Instruction Manual ...
Страница 138: ...9 20 Remote Operation Model 6485 Picoammeter Instruction Manual ...
Страница 159: ...11 CommonCommands ...
Страница 164: ...11 6 Common Commands Model 6485 Picoammeter Instruction Manual ...
Страница 165: ...12 SCPISignalOriented MeasurementCommands ...
Страница 190: ...14 12 SCPI Reference Tables Model 6485 Picoammeter Instruction Manual ...
Страница 214: ...16 14 Calibration Model 6485 Instruction Manual ...
Страница 219: ...A Specifications ...
Страница 221: ...B StatusandErrorMessages ...
Страница 227: ...C GeneralMeasurement Considerations ...
Страница 233: ...D DDCEmulationCommands ...
Страница 247: ...E ExamplePrograms ...
Страница 250: ...E 4 Example Programs Model 6485 Picoammeter Instruction Manual ...
Страница 251: ...F IEEE 488BusOverview ...
Страница 266: ...F 16 IEEE 488 Bus Overview Model 6485 Picoammeter Instruction Manual ...
Страница 267: ...G IEEE 488andSCPI ConformanceInformation ...
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