Campbell OBS-3+, Instruction Manual

Page: 44 / 54

Appendix B. Example Programs
'the true NTU. Big particles can cause errors that would skew an average
NTU = NTUX(11)
'Use the low range channel to get a more accurate measurement.
If NTU < 250 Then
'The value of 250 was chosen because it is the nominal low range value of
'this OBS sensor.
For i = 1 To n
VoltSe (NTUX(i),1,mV5000,2,1,0,_60Hz,0.001,0)
NTUX(i) = A(1) * NTUX(i)^2 + B(1) * NTUX(i) + C(1) ' V to NTU conversion
Delay(0,45,mSec) 'Delay between measurements
Next i
EndIf
SortSpa (NTUX(),21,NTUX())
NTU = NTUX(11)
SW12 (0)
'-------------------------------------------------------------------
CallTable Data_15m
NextScan
EndProg
B.1.2 CR200(X) Example Program
The following example uses the voltage curve of the calibrations certificate
provided in FIGURE 7-3. Since the coefficients of the voltage curve are used,
the multiplier for the VoltSE instruction needs to be 0.001.
The calibration values are different for each probe.
'CR200(X) Series Datalogger
'Boyd Bringhurst, CSI 3/05/08
Public batt_volt
Public NTU, NTU_SD
Public NTUarray(10)
Public n,i
Public A(2), B(2), C(2)
DataTable (NTUData,1,-1)
DataInterval (0,1,min)
Sample (1,NTU)
Sample (1,NTU_SD)
EndTable
BeginProg
n = 10
A(1) = -0.24763
B(1) = 105.69
C(1) = -0.29928
A(2) = 35.310
B(2) = 401.11
C(2) = 0.20709
Scan (5,Sec)
Battery (Batt_volt)
SWBatt (1 )
Delay (2,sec)
NOTE
B-2