PASCO CI-6729 (1X) CONDUCTIVITY SENSOR - Manual (Page 18)

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Conductivity Sensor 012–06485B
4. Set up the Conductivity Sensor according to the procedure detailed in pages 6–7 of the
manual. Select the 20k scale on the amplifier box.
➤ Calibration is not needed for this experiment.
5. Plug the Temperature Sensor into analog channel B of the interface box. In the Experiment
Setup window of Science Workshop, drag the analog plug icon to the analog channel B
icon, and select Temperature Sensor.
6. Open a Digits display by dragging Digits icon to the Temperature Sensor icon.
7. Click the Horizontal Axis Input button, and select Analog B, Temp.
8. Define a labeling scheme to identify the solutions.
9. In the Experiment Setup window, click Sampling Options, select Slow under Periodic
Samples, and set the sampling rate to 1 per 5 seconds.
10. Insert the Conductivity Electrode into the first 200 ml water sample. Turn on the hot plate
and magnetic stirrer. The heat and the stirring controls should be set to a mid-range value.
Click the REC. Tap the Conductivity Electrode occasionally to avoid the formation of air
bubbles in the electrode’s cell. When the temperature of the solution reaches 60 °C, click
STOP.
11. Remove the temperature and conductivity electrodes, and rinse them with the wash bottle.
12. Repeat steps 9 and 10 with the other solutions.
Data Analysis
1. Click the Graph display to make it active. Click the Statistics button ( ) to open the
Statistics area on the right side of the graph.
2. On the Experiment menu, select Run 1.
3. Click the Autoscale button ( ) to re-scale the Graph display to fit the data.
4. Click the Statistics Menu button ( ), and select Curve Fit
➤ Linear Fit.
5. Click on the Smart Cursor button ( ). Move the cursor to the place in the graph where
the temperature is 25 °C. Divide the value of the slope by the conductivity reading at 25 °C
and multiply by 100% to determine percent change/°C at 25 °C. Record your results in the
Data Table. (The temperature dependence of the electrical conductivity is expressed usually
expressed in this manner.)