Materials:
CBL system
TI-83 Plus graphing calculator
CHEMBIO program
Vernier adapter cable
pH electrode
pH amplifier
pH7 buffer
pH 10 buffer
distilled or de-ionized water
Calculator-to-CBL link cable
Texas Instruments AC 9201 adapter (or use batteries)
Tissue or paper towels

2 Point pH Calibration Procedure:
1. Connect the CBL System to the TI-83 Plus graphing calculator using the link cable.
2. Plug the Texas Instruments AC 9201 adapter into the CBL system
3. Plug the Vernier adapter cable into Channel 1 of the CBL system.
4. Plug the pH amplifier into the Vernier adapter cable.
5. Plug the pH electrode into the pH amplifier
6. Turn on the CBL system and the TI-83 graphing calculator.
7. Select APPS on the calculator.
8. Start the CHEMBIO program (3).
9. Press ENTER to proceed to the main menu.
10. Enter "1" as the number of probes.
11. Select pH (2) from the SELECT PROBE menu.
12. Enter "1" as the channel number.
13. Select PERFORM NEW (2) from the CALIBRATION menu.
14. Press ENTER after the system warms up for 30 seconds.
15. Remove the electrode from the bottle by loosening the lid.
16. Rinse the electrode with distilled or de-ionized water.
17. Place the electrode in pH 7 buffer.
18. Press TRIGGER on the CBL system after the readings stabilize.
19. Enter "7" as the reference point onto the calculator.
20. Rinse the electrode with distilled or de-ionized water.
21. Place the electrode in pH 10 buffer.
22. Press TRIGGER on the CBL system after the readings stabilize.
23. Enter "10" as the reference point onto the calculator.
24. Record the intercept and slope values. Testing Procedure:
1. Connect the CBL System to the TI-83 Plus graphing calculator using the link cable.
2. Plug the Texas Instruments AC 9201 adapter into the CBL system
3. Plug the Vernier adapter cable into Channel 1 of the CBL system.
4. Plug the pH amplifier into the Vernier adapter cable.
5. Plug the pH electrode into the pH amplifier
6. Turn on the CBL system and the TI-83 graphing calculator.
7. Select APPS on the calculator.
8. Start the CHEMBIO program (3).
9. Press ENTER to proceed to the main menu.
10. Select SET UP PROBES from the MAIN MENU.
11. Enter "1" as the number of probes.
12. Select pH (2) from the SELECT PROBE menu.
13. Enter "1" as the channel number.
14. Select USED STORED from the CALIBRATION menu. If you select MANUEL ENTRY, enter the intercept and slope values on the calculator.
15. Select COLLECT DATA (2) from the main menu.
16. Select SINGLE POINT (5) from the DATA COLLECTION menu.
17. Press ENTER to proceed to the main menu.
18. Remove the pH electrode from the storage bottle.
19. Rinse the tip of the electrode with stream water.
20. Place the tip of the electrode into the stream far from the shore and below the water’s surface.
21. When readings displayed on the CBL system stabilize, press ENTER to begin sampling.
22. Record the pH value displayed on the calculator screen.
23. Press ENTER, then select YES to repeat measurement.
24. Press ENTER to take a second reading.
25. Record the pH value displayed on the calculator screen.
26. Press ENTER, then select NO to return to the MAIN MENU.
27. Rinse the electrode with distilled water or de-ionized water and return it to the storage bottle.