Section 8. Operation
280
duration. Consequently, noise at 1 / (integer multiples) of the integration duration
is effectively rejected by an analog integrator. table
CRBasic Measurement
Integration Times and Codes
(p. 280)
lists three integration durations available in the
CR800 and associated CRBasic codes. If reversing the differential inputs or
reversing the excitation is specified, there are two separate integrations per
measurement; if both reversals are specified, there are four separate integrations.
Table 54.
CRBasic Measurement Integration Times and Codes
Integration Time (ms)
CRBasic Code
Comments
250 µs
250
Fast integration
16.667 ms
_60Hz
Filters 60-Hz noise
20 ms
_50Hz
Filters 50-Hz noise
8.1.2.7.1 ac Power Line Noise Rejection
Grid or mains power (50 or 60 Hz, 230 or 120 Vac) can induce electrical noise at
integer multiples of 50 or 60 Hz. Small analog voltage signals, such as
thermocouples and pyranometers, are particularly susceptible. CR800 voltage
measurements can be programmed to reject (filter) 50-Hz or 60-Hz related noise.
ac Noise Rejection on Small Signals
The CR800 rejects ac power line noise on all voltage ranges except
mV5000
and
mV2500
by integrating the measurement over exactly one ac cycle before A/D
conversion as illustrated in table
ac Noise Rejection on Small Signals
(p. 280)
and
the full cycle technique of figure
ac Power Line Noise Rejection Techniques
(p.
281).
Table 55.
ac Noise Rejection on Small Signals
Applies to all analog input voltage ranges except
mV2500
and
mV5000
.
ac Power Line Frequency
Measurement Integration
Duration
CRBasic Integration Code
60 Hz
16.667 ms
_60Hz
50 Hz
20 ms
_50Hz
Содержание CR850
Страница 2: ......
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Страница 26: ...Table of Contents 26...
Страница 30: ...Section 2 Cautionary Statements 30...
Страница 32: ...Section 3 Initial Inspection 32...
Страница 35: ...Section 4 Quickstart Tutorial 35 Figure 2 Wiring panel...
Страница 55: ...Section 4 Quickstart Tutorial 55 Figure 24 PC200W View data utility...
Страница 78: ...Section 5 System Overview 78...
Страница 80: ...Section 6 CR800 Specifications 80...
Страница 95: ...Section 7 Installation 95 Figure 35 DevConfig OS download window Figure 36 Dialog box confirming OS download...
Страница 104: ...Section 7 Installation 104 Figure 43 Include File settings via DevConfig Figure 44 Include File settings via PakBusGraph...
Страница 267: ...Section 7 Installation 267 Figure 84 Running average signal attenuation...
Страница 268: ...Section 7 Installation 268...
Страница 384: ...Section 8 Operation 384 Figure 113 Using the keyboard display...
Страница 385: ...Section 8 Operation 385 8 8 1 Data Display Figure 114 Displaying data with the keyboard display...
Страница 387: ...Section 8 Operation 387 Figure 116 Real time custom...
Страница 388: ...Section 8 Operation 388 8 8 1 3 Final Storage Tables Figure 117 Final storage tables...
Страница 389: ...Section 8 Operation 389 8 8 2 Run Stop Program Figure 118 Run Stop Program...
Страница 390: ...Section 8 Operation 390 8 8 3 File Display Figure 119 File display...
Страница 396: ...Section 8 Operation 396...
Страница 402: ...Section 9 Maintenance 402...
Страница 450: ...Section 11 Glossary 450...
Страница 504: ...Appendix A CRBasic Programming Instructions 504...
Страница 526: ...Appendix B Status Table and Settings 526...
Страница 530: ...Appendix C Serial Port Pinouts 530...
Страница 536: ...Appendix E FP2 Data Format 536...
Страница 550: ...Appendix F Other Campbell Scientific Products 550...
Страница 564: ...Index 564 WriteIO 464 Writing Program 108 X XML 448 XOR 473 Y Y intercept 141 142 Z Zero 155 166 Zero Basis 151...
Страница 565: ......