Section 7. Installation
240
'measurements), the routine is complete. Note the new values in variables FlowMultiplier and
'FlowOffest. Now enter a new value in the simulated sensor signal as follows and note
'how the new multiplier and offset scale the measurement:
' SimulatedFlowSignal = 1000
'NOTE: This program places a .cal file on the CPU: drive of the CR3000. The .cal file must
'be erased to reset the demonstration.
'DECLARE SIMULATED SIGNAL VARIABLE AND SET INITIAL MAGNITUDE
Public SimulatedFlowSignal = 300 'Excitation mV, second setting is 550
'DECLARE CALIBRATION STANDARD VARIABLE AND SET MAGNITUDE
Public
KnownFlow = 30
'Known flow, second setting is 10
'DECLARE MEASUREMENT RESULT VARIABLE.
Public
Flow
'DECLARE MULTIPLIER AND OFFSET RESULT VARIABLES AND SET INITIAL MAGNITUDES
Public
FlowMultiplier = 1
Public
FlowOffset = 0
'DECLARE VARIABLE FOR FieldCal() CONTROL
Public
CalMode
'DECLARE DATA TABLE FOR RETRIEVABLE CALIBRATION RESULTS
DataTable
(CalHist,NewFieldCal,200)
SampleFieldCal
EndTable
BeginProg
'LOAD CALIBRATION CONSTANTS FROM FILE CPU:CALHIST.CAL
'Effective after the zero calibration procedure (when variable CalMode = 6)
LoadFieldCal
(true)
Scan
(100,mSec,0,0)
'SIMULATE SIGNAL THEN MAKE THE MEASUREMENT
'Multiplier calibration is applied when variable CalMode = 6
ExciteV
(Vx1,SimulatedFlowSignal,0)
VoltSE
(Flow,1,mV5000,1,1,0,250,FlowMultiplier,FlowOffset)
'PERFORM A MULTIPLIER CALIBRATION.
'Start by setting variable CalMode = 1. Finished when variable CalMode = 6.
'FieldCal(Function, MeasureVar, Reps, MultVar, OffsetVar, Mode, KnownVar, Index, Avg)
FieldCal
(2,Flow,1,FlowMultiplier,FlowOffset,CalMode,KnownFlow,1,30)
'If there was a calibration, store it into a data table
CallTable
(CalHist)
NextScan
EndProg
7.7.12.5.4
FieldCal() Slope (Opt 3) Example
Most CRBasic measurement instructions have a multiplier and offset parameter.
FieldCal() Option 3 adjusts the multiplier argument such that the output of the
sensor being calibrated is set to a value consistent with the linear relationship that
intersects two known points sequentially entered in the FieldCal() KnownVar
Summary of Contents for CR3000 Micrologger
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Page 485: ...Section 8 Operation 485 8 11 2 Data Display FIGURE 110 Keyboard and Display Displaying Data ...
Page 487: ...Section 8 Operation 487 FIGURE 112 CR1000KD Real Time Custom ...
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Page 564: ...Section 11 Glossary 564 FIGURE 126 Relationships of Accuracy Precision and Resolution ...
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