Campbell Scientific CS511 Dissolved Oxygen Probe - Manual (Page 21)

CS511-L Dissolved Oxygen Probe
4) Place the CS511 in air away from direct sunlight with the membrane facing
upward.
5) Place a drop of clean water on the membrane.
6) Wait for readings to stabilize. This may take 15 minutes or more.
7) Determine the air temperature and barometric pressure.
8) Using a calibration chart such as that provided in Appendix A, determine the
oxygen concentration of the air.
9) Use the following equation to calculate the multiplier:
M = P/R
where:
M = Multiplier
P = Concentration in PPM of the air (from the calibration chart)
R = The signal output of the probe when using a multiplier of one
10) Change the multiplier in the datalogger program from one to the calculated
number (see Section 4.2, Use SCWin to Program Datalogger and Generate
Wiring Diagram, or Section 7.2, Programming).
Instead of step 10, the multiplier can be entered using a separate instruction in
the program. This will allow a new multiplier to be added to the program
without rewriting, compiling, and downloading the program to the datalogger.
For this method, CRBasic dataloggers can use the following expression. The
multiplier value is entered into the expression through the Public Table using
the numeric display in PC200W, LoggerNet, PC400, PConnect, PConnectCE,
or datalogger keyboard display.
CRBasic Expression for Entering Multiplier:
DOppm = DOMult * DOmV
Edlog dataloggers use Instruction 36. The multiplier is entered into an input
location called DOmult using the numeric display in PC200W, PC208W,
LoggerNet, PC400, PConnect, PConnectCE, or the datalogger keyboard
display.
Edlog Instruction 36 for Entering Multiplier:
57: Z=X*Y (P36)
1: 1
X Loc [ DOmV ]
2: 2 Y Loc [ DOmult ]
3: 3 Z Loc [ DOppm ]
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