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G.1.12, 50 hz measurement example — one cdm-vw300, two, Steinc(8) – Campbell Scientific CDM-VW300 Series Dynamic Vibrating-Wire Analyzer System User Manual

Page 111: Appendix g. crbasic program library, G-19

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Appendix G. CRBasic Program Library

'Calculate static digits reading (for troubleshooting)

StaticDigits(1)

=

StaticStrain(1)/GageFactor/NomBatchFactor

StaticDigits(2)

=

StaticStrain(2)/GageFactor/NomBatchFactor

'Now shift the given StaticStrain using the Offset/Baseline reading to obtain

'Final/adjusted StaticStrain

StaticStrain(1)

=

StaticStrain(1) + StrainBL(1) : StaticStrain(2)

=

StaticStrain(2) + _

StrainBL(2)

'Calculate static frequency from static digits (for troubleshooting)

StaticFreq(1)

=

SQR(StaticDigits(1)*1000) : StaticFreq(2)

=

SQR(StaticDigits(2)*1000)

CallTable

static

EndIf

NextScan

EndProg

SlowSequence

Scan

(5,sec,10,0)

'Rainflow-Histogram call must be in a slow sequence scan

CDM_VW300Rainflow

(CPI_ADDR,RF1(),RF2(),RF3(),RF4(),RF5(),RF6(),RF7(),RF8())

CallTable

rainflhist

NextScan

EndProg

G.1.12 50 Hz Measurement Example — One CDM-VW300, Two

Geokon 4000 Sensors with FieldCal() and CardOut() to
CF

'===Geokon4000-50Hz2ChEventCard_4-22-13.CR3===

'CR3000 datalogger

'CDM-VW300 vibrating-wire analyzer

'Program to read 50-Hz dynamic data from one CDM-VW300 measuring two Geokon 4000

strain gages.

' Write data to CF card at each event.

' Demonstrate use of CardOut(), DataEvent(), and DataInterval() to conserve data storage.

'IMPORTANT -- Ensure that the CPI address coded on the following line matches the address

'reported for the attached analyzer in the DevConfig or DVWTool software.

Const

CPI_ADDR

=

1

'<<<<<<<<<<<<<

'Constants specific to the Geokon 4000 strain gages

Const

GageFactor

=

4.062

'G = 4.062 - Gage factor taken from sensor manual

Const

NomBatchFactor

=

0.97

'B=0.97 - Batch Factor taken from calibration sheet provided with

'sensors

'Output will be in Strain, not Digits nor Frequency

Public

Strain(2) : Units Strain()

=

Microstrain

'Measured strain output in units of Microstrain

Public

StrainBL(2) : Units Strain()

=

Microstrain

'Baseline/offset strain reading in units of

Microstrain (for calibration)

Public

DCode(2)

As Long

'Dynamic diagnostic code

Public

StaticStrain(2) : Units StaticStrain()

=

Microstrain

'Static (1Hz) strain reading in

microstrain

Public

StaticDigits(2)

'Calculated Static (1Hz) Digits output (for troubleshooting)

Public

StaticFreq(2) : Units StaticFreq)

=

Hz

'Calculated Frequency (1Hz) from static digits

'(

for troubleshooting)

Public

Temp(2) : Units Temp()

=

DegC

' Temperature in DegC

Public

TempBL(2) : Units TempBL()

=

DegC

' Temperature Baseline in DegC

Public

StrainStdDev(2) : Units StrainStdDev()

=

Microstrain

'StdDev of dynamic strain readings

Public

ZeroMode

'Mode variable for baseline/offset zeroing calibration

'Configure the CDM-VW300 device

Dim

Enable(2)

As Long

=

{ 1, 1}

Dim

Max_AMP(2)

=

{ 0.002, 0.002}

Dim

F_Low(2)

=

{ 300, 300}

Dim

F_High(2)

=

{ 6000, 6000}

'Use Hz^2 (1) instead of Hz (0) so we can get to digits

G-19