Specifications

Section 11. Programming Resource Library
11-8
EXAMPLE 11.1-3. FieldCal multiplier and offset demonstration program.
'Jumper Vx/EX1 to SE8(4L) to simulate a sensor
Public mV 'Excitation mV Output
Public KnownFlow 'Known Water Flow
Public CalMode 'Calibration Trigger
Public Multiplier 'Sensitivity
Public Offset 'Offset (Starts at zero, not changed)
Public WaterFlow 'Water Flow
'Data Storage Output of Calibration Data -- stored whenever a calibration occurs
DataTable(CalHist,NewFieldCal,200)
SampleFieldCal
EndTable
BeginProg
Multiplier = 1
Offset = 0
KnownFlow = 0
LoadFieldCal(true) 'Load the CAL File, if possible
Scan(100,mSec,0,0)
'Simulate measurement by exciting channel Vx/EX1
ExciteV(Vx1,mV,0)
'Make the calibrated measurement
VoltSE(WaterFlow,1,mV2500,8,1,0,250,Multiplier,Offset)
'Perform a calibration if CalMode = 1
FieldCal(2,WaterFlow,1,Multiplier,Offset,CalMode,KnownFlow,1,30)
'If there was a calibration, store it into a data table
CallTable(CalHist)
NextScan
EndProg
11.1.5.4 Two Point Slope Only (Option 3)
Some measurement applications do not require determination of offset. Wave
form analysis, for example, may only require relative data to characterize
change.
Case: A soil water sensor is to be use to detect a pulse of water moving
through soil. To adjust the sensitivity of the sensor, two soil samples, with
volumetric water contents of 10 and 35, will provide two known points.
The following procedure sets the sensitivity of a simulated soil water content
sensor.