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3-6
Range, Digits, Rate, and Filter
Rate
The RATE key selects the integration time of the A/D converter. This is the period of time the
input signal is measured (also known as aperture). 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, the Model 2182 has a parabola-like shape for its speed vs. noise characteristics
and is shown in
. The Model 2182 is optimized for the 1 PLC to 5 PLC reading rate.
At these speeds (Lowest noise region in the graph), the Model 2182 will make corrections for
its own internal drift and still be fast enough to settle a step response <100ms.
Figure 3-1
Speed vs. noise characteristics
You can have a separate rate setting for voltage and temperature functions. The rate setting
for a voltage function applies to the other voltage function. For example, if you set DCV1 for
0.1 PLC (fast), DCV2 will also be set for 0.1 PLC (fast). Similarly, the rate setting for a
temperature function applies to the other temperature function. Setting TEMP1 for 5 PLC
(slow), also sets TEMP2 for 5 PLC (slow).
Front panel RATE selections are explained as follows:
•
0.1 PLC — Selects the fastest front panel integration time. Select 0.1 PLC (fast) if speed
is of primary importance (at the expense of increased reading noise).
•
1 PLC — Selects a medium integration time. Select 1 PLC (medium) when a
compromise between noise performance and speed is acceptable.
•
5 PLC — Selects the slowest front panel integration time. Selecting 5 PLC (slow)
provides better noise performance at the expense of speed.
Lowest
noise
region
Voltage
Noise
166.7
µ
s
16.67ms
83.33ms
Aperture Time
1s
Содержание 2182
Страница 1: ...www tek com keithley Model 2182 2182A Nanovoltmeter User s Manual 2182A 900 01 Rev B May 2017...
Страница 18: ......
Страница 22: ......
Страница 23: ...1 Getting Started Getting Started...
Страница 41: ...2 VoltageandTemperature Measurements Voltageand Temperature Measurements...
Страница 68: ...2 28 Voltage and Temperature Measurements...
Страница 69: ...3 Range Digits Rate andFilter Range Digits Rate andFilter...
Страница 82: ...3 14 Range Digits Rate and Filter...
Страница 83: ...4 Relative mX b and Percent Relative mX b andPercent...
Страница 91: ...5 RatioandDelta Ratioand Delta...
Страница 117: ...6 Buffer Buffer...
Страница 123: ...7 Triggering Triggering...
Страница 140: ...7 18 Triggering...
Страница 141: ...8 Limits Limits...
Страница 149: ...9 SteppingandScanning Steppingand Scanning...
Страница 168: ...9 20 Stepping and Scanning...
Страница 169: ...10 AnalogOutput Analog Output...
Страница 175: ...11 RemoteOperation Remote Operation...
Страница 205: ...12 CommonCommands Common Commands...
Страница 221: ...13 SCPISignalOriented Measurement Commands SCPISignalOri entedMeasure ment Commands...
Страница 225: ...14 SCPIReferenceTables SCPIRefer enceTables...
Страница 239: ...15 AdditionalSCPI Commands Additional SCPICom mands...
Страница 260: ...15 22 Additional SCPI Commands...
Страница 261: ...A Specifications Specifications...
Страница 263: ...B Statusand ErrorMessages StatusandError Messages...
Страница 268: ...B 6 Status and Error Messages...
Страница 269: ...C Measurement Considerations Measurement Consider ations...
Страница 278: ...C 10 Measurement Considerations...
Страница 279: ...D Model182Emulation Commands Model182 EmulationCom mands...
Страница 284: ...D 6 Model 182 Emulation Commands...
Страница 285: ...E Example Programs ExamplePro grams...
Страница 293: ...F IEEE 488 BusOverview IEEE 488Bus Overview...
Страница 307: ...G IEEE 488andSCPI ConformanceInformation IEEE 488and SCPIConform anceInforma tion...
Страница 310: ...G 4 IEEE 488 and SCPI Conformance Information...
Страница 311: ...H Measurement Queries Measurement Queries...
Страница 316: ...H 6 Measurement Queries...
Страница 317: ...I Delta PulseDelta and DifferentialConductance Delta Pulse Deltaand Dif ferentialCon ductance...