Section 7. Installation
162
'Data Storage Output of Calibration Data
─
stored whenever a calibration occurs
DataTable
(CalHist,NewFieldCal,200)
SampleFieldCal
EndTable
BeginProg
Multiplier = 1
Offset = 0
KnownWC = 0
LoadFieldCal
(true)
'Load the CAL File, if possible
Scan
(100,mSec,0,0)
'Simulate measurement by exciting channel VX1/EX1
ExciteV
(Vx1,mV,0)
'Make the calibrated measurement
VoltSE
(RelH2OContent,1,mV2500,6,1,0,250,Multiplier,Offset)
'Perform a calibration if CalMode = 1
FieldCal
(3,RelH2OContent,1,Multiplier,Offset,CalMode,KnownWC,1,30)
'If there was a calibration, store it into a data table
CallTable
(CalHist)
NextScan
EndProg
7.8.1.6 FieldCalStrain() Demonstration Program
Strain-gage systems consist of one or more strain gages, a resistive bridge in
which the gage resides, and a measurement device such as the CR800 datalogger.
The
FieldCalStrain()
instruction facilitates shunt calibration of strain-gage
systems and is designed exclusively for strain applications wherein microstrain is
the unit of measure. The
FieldCal()
instruction (
FieldCal() Demonstration
Programs
(p. 154)
) is typically used in non-microstrain applications.
Shunt calibration of strain-gage systems is common practice. However, the
technique provides many opportunities for misapplication and misinterpretation.
This section is not intended to be a primer on shunt-calibration theory, but only to
introduce use of the technique with the CR800 datalogger. Campbell Scientific
strongly urges users to study shunt-calibration theory from other sources. A
thorough treatment of strain gages and shunt-calibration theory is available from
Vishay at:
http://www.vishaypg.com/micro-measurements/stress-analysis-strain-
gages/calculator-list/
Campbell Scientific applications engineers also have resources that may assist
users with strain-gage applications.
FieldCalStrain()
shunt-calibration concepts:
1. Shunt calibration does not calibrate the strain gage itself.
2. Shunt calibration does compensate for long leads and non-linearity in the
resistive bridge. Long leads reduce sensitivity because of voltage drop.
Содержание CR850
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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...
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