Materials:
CBL system
TI-83 Plus graphing calculator
CHEMBIO program
Vernier Dissolved Oxygen Probe
Vernier adapter cable
Calculator-to-CBL link cable
Texas Instruments AC 9201 adapter (or use batteries)
DO Electrode Filling Solution
Sodium Sulfite Calibration Solution
100% calibration bottle
Distilled or de-ionized water
Tissues or paper towels
Pipet (1ml)
250ml beaker
cup attached to a rod
lab wipe tissue
Calibration and Polarization Procedures:
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 Vernier Dissolved Oxygen Probe into the Vernier adapter
cable.
5. Turn on the CBL system and the TI-83 graphing calculator.
6. Press APPS on the calculator and in the CHEMBIO program.
7. Select SET UP PROBES (1) from the MAIN MENU
8. Enter "1" as the number of probes.
9. Select MORE PROBES (7) from the SELECT PROBE menu.
10. Select D. Oxygen (1) from the SELECT PROBE menu.
11. Enter "1" as the channel number.
12. Unscrew the membrane cap from the tip of the Dissolved Oxygen probe.
13. Using a pipet, fill the membrane cap with 1 ml of DO Electrode Filling
Solution.
14. Carefully screw back the membrane cap back onto the electrode.
15. Rinse electrode with distilled or de-ionized water
16. Wipe electrode with lab wipe and be careful not to touch the membrane
itself.
17. Place the probe into a 250ml beaker containing distilled or de-ionized
water and let it set until after it is polarized.
18. Select POLARIZE PROBE (4) from the CALIBRATION menu.
19. Wait 30 minutes while the probe polarizes. Do not disconnect the
probe from the CBL.
20. After 30 minutes, press ENTER to return to the CALIBRATION menu.
21. Select PERFORM NEW from the CALIBRATION menu.
22. Remove the probe from the beaker.
23. Place the tip of the probe at an angle into the Sodium Sulfite Calibration
Solution.
24. Tap the side of the bottle with the probe to dislodge any air bubbles.
25. The readings should range from 0.2 to 0.5 V range.
26. When the readings stabilize on the CBL screen, press TRIGGER.
27. Enter "0" on the calculator as the reference point.
28. To prevent oxygen from entering into the Sodium Sulfite Calibration
Solution, gently squeeze the bottle so the level of solution is at the
very top of the bottle neck. Screw on the lid.
29. Rinse the probe with distilled o de-ionized water.
30. Unscrew the lid of the calibration bottle.
31. Slide the lid and the grommet about _ inch into the probe body.
32. Add distilled or de-ionized water to the bottle about a _ inch.
Make sure the probe’s membrane does not get wet during this step.
33. Screw the bottle into the cap.
34. Keep the probe in this position for about 1 minute.
35. The readings should be in the range of 2.0 to 3.0 V.
36. Allow the voltage reading on the CBL system to stabilize before
pressing the TRIGGER button.
37. If you know the site’s elevation (feet), find the barometric
pressure (mm Hg) by looking at TABLE 2.
38. If you know the site’s air temperature (degrees Celsius) and
the barometric pressure (mm Hg), find the correct saturated dissolved-oxygen
value (mg/L) from TABLE 1.
39. Enter this value into the calculator and press ENTER to return to
the MAIN MENU. If you are calibrating in %saturation (instead of mg/L)
enter "100".
40. Keep a record of the intercept and slope values displayed on the
calculator.
41. With the membrane cap still filled with DO electrode filing solution,
fill the calibration bottle full with distilled or de-ionized water.
42. Fit the probe down into the lid and tighten the lid onto the bottle.
Make sure the probe’s tip is submerged in the water until you are
ready to take samples (within 24 hours).
Testing Procedures:
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 Vernier Dissolved Oxygen Probe into the Vernier adapter
cable.
5. Turn on the CBL system and the TI-83 graphing calculator.
6. Press APPS on the calculator and in the CHEMBIO program.
7. Select SET UP PROBES (1) from the MAIN MENU
8. Enter "1" as the number of probes.
9. Select MORE PROBES (7) from the SELECT PROBE menu.
10. Select D. Oxygen (1) from the SELECT PROBE menu.
11. Enter "1" as the channel number.
12. Press ENTER to return to the MAIN MENU.
13. Select MANUEL ENTRY from the CALIBRATION MENU and enter the slope
and intercept values previously recorded.
14. Select COLLECT DATA (2).
15. Select SINGLE POINT from the DATA COLLECTION (5) menu.
16. Remove the probe from the calibration bottle.
17. Rinse the tip of the probe in the sample water.
18. Place the tip of the probe into water collected from the stream
far from the shore and below the water’s surface.
19. Gently and slowly stir the probe in the water to help prevent the
oxygen level from dropping.
20. After the reading on the CBL screen stabilizes, press ENTER to begin
sampling.
21. After 25 seconds, the dissolved oxygen concentration will appear
on the calculator screen.
22. Keep the site and value.
23. Press ENTER , then select YES to repeat the measurement for another
site, or NO to return to the main menu
24. Refill the calibration bottle with distilled or de-ionized water
if you will do more testing and put the probe back into the lid and
submerged in the water.
25. If you are finished the DO test, unscrew the bottle from the lid,
then slide the lid and the grommet from the end of the electrode.
26. Remove the membrane cap and rinse the inside and outside of the
cap with distilled or de-ionized water.
27. Shake the membrane cap dry.
28. Rinse the inner anode and cathode inner elements and blot dry with
a lab wipe.
29. Reinstall the membrane cap loosley onto the electrode body for storage
|
Table 1: Concentration
(mg/L) of Dissolved O2 at Saturation |
|
|
770 mm |
760 mm |
750 mm |
740 mm |
730 mm |
720 mm |
710 mm |
700 mm |
690 mm |
680 mm |
670 mm |
660 mm |
|
0°C |
14.76 |
14.57 |
14.38 |
14.19 |
13.99 |
13.80 |
13.61 |
13.42 |
13.23 |
13.04 |
12.84 |
12.65 |
|
1°C |
14.38 |
14.19 |
14.00 |
13.82 |
13.63 |
13.44 |
13.26 |
13.07 |
12.88 |
12.70 |
12.51 |
12.32 |
|
2°C |
14.01 |
13.82 |
13.64 |
13.46 |
13.28 |
13.10 |
12.92 |
12.73 |
12.55 |
12.37 |
12.19 |
12.01 |
|
3°C |
13.65 |
13.47 |
13.29 |
13.12 |
12.94 |
12.76 |
12.59 |
12.41 |
12.23 |
12.05 |
11.88 |
11.70 |
|
4°C |
13.31 |
13.13 |
12.96 |
12.79 |
12.61 |
12.44 |
12.27 |
12.10 |
11.92 |
11.75 |
11.58 |
11.40 |
|
5°C |
12.97 |
12.81 |
12.64 |
12.47 |
12.30 |
12.13 |
11.96 |
11.80 |
11.63 |
11.46 |
11.29 |
11.12 |
|
6°C |
12.66 |
12.49 |
12.33 |
12.16 |
12.00 |
11.83 |
11.67 |
11.51 |
11.34 |
11.18 |
11.01 |
10.85 |
|
7°C |
12.35 |
12.19 |
12.03 |
11.87 |
11.71 |
11.55 |
11.39 |
11.23 |
11.07 |
10.91 |
10.75 |
10.59 |
|
8°C |
12.05 |
11.90 |
11.74 |
11.58 |
11.43 |
11.27 |
11.11 |
10.96 |
10.80 |
10.65 |
10.49 |
10.33 |
|
9°C |
11.77 |
11.62 |
11.46 |
11.31 |
11.16 |
11.01 |
10.85 |
10.70 |
10.55 |
10.39 |
10.24 |
10.09 |
|
10°C |
11.50 |
11.35 |
11.20 |
11.05 |
10.90 |
10.75 |
10.60 |
10.45 |
10.30 |
10.15 |
10.00 |
9.86 |
|
11°C |
11.24 |
11.09 |
10.94 |
10.80 |
10.65 |
10.51 |
10.36 |
10.21 |
10.07 |
9.92 |
9.78 |
9.63 |
|
12°C |
10.98 |
10.84 |
10.70 |
10.56 |
10.41 |
10.27 |
10.13 |
9.99 |
9.84 |
9.70 |
9.56 |
9.41 |
|
13°C |
10.74 |
10.60 |
10.46 |
10.32 |
10.18 |
10.04 |
9.90 |
9.77 |
9.63 |
9.49 |
9.35 |
9.21 |
|
14°C |
10.51 |
10.37 |
10.24 |
10.10 |
9.96 |
9.83 |
9.69 |
9.55 |
9.42 |
9.28 |
9.14 |
9.01 |
|
15°C |
10.29 |
10.15 |
10.02 |
9.88 |
9.75 |
9.62 |
9.48 |
9.35 |
9.22 |
9.08 |
8.95 |
8.82 |
|
16°C |
10.07 |
9.94 |
9.81 |
9.68 |
9.55 |
9.42 |
9.29 |
9.15 |
9.02 |
8.89 |
8.76 |
8.63 |
|
17°C |
9.86 |
9.74 |
9.61 |
9.48 |
9.35 |
9.22 |
9.10 |
8.97 |
8.84 |
8.71 |
8.58 |
8.45 |
|
18°C |
9.67 |
9.54 |
9.41 |
9.29 |
9.16 |
9.04 |
8.91 |
8.79 |
8.66 |
8.54 |
8.41 |
8.28 |
|
19°C |
9.47 |
9.35 |
9.23 |
9.11 |
8.98 |
8.86 |
8.74 |
8.61 |
8.49 |
8.37 |
8.24 |
8.12 |
|
20°C |
9.29 |
9.17 |
9.05 |
8.93 |
8.81 |
8.69 |
8.57 |
8.45 |
8.33 |
8.20 |
8.08 |
7.96 |
|
21°C |
9.11 |
9.00 |
8.88 |
8.76 |
8.64 |
8.52 |
8.40 |
8.28 |
8.17 |
8.05 |
7.93 |
7.81 |
|
22°C |
8.94 |
8.83 |
8.71 |
8.59 |
8.48 |
8.36 |
8.25 |
8.13 |
8.01 |
7.90 |
7.78 |
7.67 |
|
23°C |
8.78 |
8.66 |
8.55 |
8.44 |
8.32 |
8.21 |
8.09 |
7.98 |
7.87 |
7.75 |
7.64 |
7.52 |
|
24°C |
8.62 |
8.51 |
8.40 |
8.28 |
8.17 |
8.06 |
7.95 |
7.84 |
7.72 |
7.61 |
7.50 |
7.39 |
|
25°C |
8.47 |
8.36 |
8.25 |
8.14 |
8.03 |
7.92 |
7.81 |
7.70 |
7.59 |
7.48 |
7.37 |
7.26 |
|
26°C |
8.32 |
8.21 |
8.10 |
7.99 |
7.89 |
7.78 |
7.67 |
7.56 |
7.45 |
7.35 |
7.24 |
7.13 |
|
27°C |
8.17 |
8.07 |
7.96 |
7.86 |
7.75 |
7.64 |
7.54 |
7.43 |
7.33 |
7.22 |
7.11 |
7.01 |
|
28°C |
8.04 |
7.93 |
7.83 |
7.72 |
7.62 |
7.51 |
7.41 |
7.30 |
7.20 |
7.10 |
6.99 |
6.89 |
|
29°C |
7.90 |
7.80 |
7.69 |
7.59 |
7.49 |
7.39 |
7.28 |
7.18 |
7.08 |
6.98 |
6.87 |
6.77 |
|
30°C |
7.77 |
7.67 |
7.57 |
7.47 |
7.36 |
7.26 |
7.16 |
7.06 |
6.96 |
6.86 |
6.76 |
6.66 |
|
31°C |
7.64 |
7.54 |
7.44 |
7.34 |
7.24 |
7.14 |
7.04 |
6.94 |
6.85 |
6.75 |
6.65 |
6.55 |
|
Table 2: Approximate
Barometric Pressure at Different Elevations |
|
Elevation
(feet) |
Pressure
(mm Hg) |
Elevation
(feet) |
Pressure
(mm Hg) |
Elevation
(feet) |
Pressure
(mm Hg) |
|
0 |
760 |
2000 |
708 |
4000 |
659 |
|
250 |
753 |
2250 |
702 |
4250 |
653 |
|
500 |
746 |
2500 |
695 |
4500 |
647 |
|
750 |
739 |
2750 |
689 |
4750 |
641 |
|
1000 |
733 |
3000 |
683 |
5000 |
635 |
|
1250 |
727 |
3250 |
677 |
5250 |
629 |
|
1500 |
720 |
3500 |
671 |
5500 |
624 |
|
1750 |
714 |
3750 |
665 |
5750 |
618 |
