Campbell Scientific 109SS Temperature Probe - Manual (Page 13)

Model 109SS Temperature Probe
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.
If the 109SS probe is to be used with long cable lengths or in electrically noisy
environments, consider employing the measurement programming techniques
outlined in Section 8.3, Electrically Noisy Environments, and Section 8.4, Long
Cable Lengths.
Details of 109SS probe measurement and linearization of the thermistor output
are provided in Section 8.2, Measurement and Output Linearization.
7.2.1 CRBasic
The Therm109() measurement instruction programs most CRBasic
dataloggers (CR200(X) series, CR800 series, CR1000, CR3000, CR5000) to
measure the 109SS probe. It makes a half-bridge resistance measurement and
converts the result to temperature using the Steinhart-Hart equation (see
Section 8.2, Measurement and Output Linearization, for more information):
Therm109 (Dest,Reps,SEChan,VxChan,SettlingTime,Integ,Mult,Offset)
The instruction for CR200(X) series dataloggers excludes the Settling Time
and Integration parameters.
Variations:
• Temperature reported as °C — set Mult to 1 and Offset to 0
• Temperature reported as °F — set Mult to 1.8 and Offset to 32
• Ac mains noise filtering — set Integ to _60Hz or _50Hz (see Section
8.3, Electrically Noisy Environments)
• Compensate for long cable lengths — Set SettlingTime to 20000 (see
Section 8.4, Long Cable Lengths)
7.2.2 Edlog
The AC Half Bridge (P5) instruction programs Edlog dataloggers (CR10(X),
CR510, CR500, CR23X, 21X, and CR7(X)) to measure the 109SS probe in a
half-bridge configuration. Polynomial (P55) applies the Steinhart-Hart
equation using a fifth-order polynomial to convert the measurement to
temperature (see Section 8.2, Measurement and Output Linearization, for more
information):
NOTE
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