Campbell Scientific CSIM11 pH and ORP Sensors - Manual (Page 19)

CSIM11 pH and ORP Probes
Short Cut cannot edit programs after they are imported and edited
in CRBasic Editor.
A Short Cut tutorial is available in Section 4, Quickstart. If you wish to import
Short Cut code into either Edlog or CRBasic Editor to create or add to a
customized program, follow the procedure in Appendix A.1, Importing Short
Cut Code into a Program Editor. Programming basics for CRBasic and Edlog
dataloggers are provided in the following sections. Complete program
examples for select dataloggers can be found in Appendix B, Example
Programs.
7.4.1 Direct Measurement, Not Temperature Compensated
Make the measurement using a differential voltage instruction ( VoltDiff()
instruction in CRBasic or Volt (Diff) (P2) in Edlog). An example from each
language follows. For ORP, the multiplier would be one and the offset would
be zero.
CRBasic
VoltDiff (pH,1,mV2500,1,True ,0,_60Hz,-0.01695,7)
Edlog
1: Volt (Diff) (P2)
1: 1
Reps
2: 5 2500 mV slow Range ;Use 4 for 21X
3: 1 IN Chan
4: 1 Loc [ pH ]
5: -.01695 Mult ;Mult = 1 for ORP
6: 7 Offset ;Offset = 0 for ORP
7.4.2 Temperature Compensation of pH Measurement
ORP measurements are usually not temperature compensated.
Therefore, CSIM11-ORP users can skip Section 7.4.2 since it
pertains to pH probes only.
The CSIM11 pH probe does not automatically correct temperature effects. To
compensate for temperature variations, install a submersible temperature probe
(such as Campbell Scientific’s 107 thermistor) next to the pH probe.
Temperature compensation can be calculated after the data has been retrieved
from the field datalogger, or immediately using datalogger processing
instructions. The first method requires storing the raw pH measurement and
the temperature measurement in datalogger final storage. After retrieving data,
raw values are processed to obtain compensated values. The second method is
to program the datalogger to process the raw data after each measurement
sequence. Both the raw data and the temperature corrected pH can be saved at
the user's discretion.
NOTE
NOTE
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