Specifications

Section 11. Programming Resource Library
11-6
EXAMPLE 11.1-2. FieldCal offset demonstration program.
'Jumper EX1 to SE8(4L) to simulate a sensor
Public mV 'Excitation mV Output
Public KnownSalt 'Known Salt Concentration
Public CalMode 'Calibration Trigger
Public Multiplier 'Multiplier (Starts at .05 mg / liter / mV, does not change)
Public Offset 'Offset (Starts at zero, not changed)
Public SaltContent 'Salt Concentration
'Data Storage Output of Calibration Data -- stored whenever a calibration occurs
DataTable(CalHist,NewFieldCal,200)
SampleFieldCal
EndTable
BeginProg
Multiplier = .05
Offset = 0
KnownSalt = 0
LoadFieldCal(true) 'Load the CAL File, if possible
Scan(100,mSec,0,0)
'Simulate measurement by exciting channel EX1
ExciteV(Vx1,mV,0)
'Make the calibrated measurement
VoltSE(SaltContent,1,mV2500,8,1,0,250,Multiplier,Offset)
'Perform a calibration if CalMode = 1
FieldCal(1,SaltContent,1,Multiplier,Offset,CalMode,KnownSalt,1,30)
'If there was a calibration, store it into a data table
CallTable(CalHist)
NextScan
EndProg
11.1.5.3 Two Point Slope and Offset (Option 2)
Case: A meter measures the volume of water flowing through a pipe.
Multiplier and offset are known to drift, so a two-point calibration is required
periodically at known flow rates. The following procedure adjusts multiplier
and offset to correct for meter drift as shown in the calibration report below.
Note that the flow meter outputs milliVolts inversely proportional to flow.