ACCUMET AB15 PH METER INSTRUCTIONS

Measuring pH

1. Make sure the electrode is filled with saturated potassium chloride (the liquid level should be at least 1/4 inch from the top). If the level is low see the "Electrode Maintenance" section below.
2. Push the standby [stdby] button to activate pH meter
3. Push [mode] until you get to the pH mode
4. "Measure" should be displayed on the top left of the screen
5. Remove the electrode from the pH 7 storage buffer, rinse with distilled water and carefully dry with a Kimwipe
6. Place the electrode in the standard buffer closest to your ending pH. Make sure the probe isn't touching the bottom of the vial. Stir, moderately, (there is a little "flea" stir bar in the vial)
7. Allow sufficient time for the measurement to stabilize (the meter will read "stable") If the reading is close to what it should be (+/- 0.05) go ahead and rinse off the probe and use it as is
8. If the reading is off by more, you should standardize the probe against the same buffer

1. Place the electrode in the buffer you are going to standardize. Once the pH reading has stabilized, press the standardize [std] button once (the selected buffer group will be displayed briefly, eg. 2,4,7,10,12) and let the meter stabilize again. If you want to use standards not included in this list, you will need to clear the old standards and select new ones (see Setting Up New Standards section below).
2. Press [std] again. The meter will automatically recognize the buffer and flash the value on the screen. When "stable" appears the buffer value is entered and the meter returns to the "Measure" mode. If the pH of the standard is still off you may want to run the standardization again.
3. If "good electrode" is not displayed you need to clear out the existing standardization and re standardize against at least 2 buffers

1. Push the [setup] button twice (the screen should read "buffer 2 4 7 10 12") push [enter]
   
2. If you want to change any of the other settings (centigrade vs. farenheit or the number of decimal points displayed) push the [setup] button until you get what you want and hit [enter] to save your selection
3. After you've cleared the old settings go through the standardization procedure listed above with 2 or more standard buffers. Making certain to rinse the electrode between standards
4. After measuring at least two standards, the meter calculates the slope between the two points and if it is >90 it will give you a "Good Electrode" message, meaning it is OK to use.

1. Check the electrode/pH meter connections.
2. Make sure the electrode is filled with saturated potassium chloride, see Electrode Maintenance section below.
3. Clear out the old standardization settings and start over.
4. If you get a electrode error message again, the electrode may be bad. There should be a spare electrode in the office.

1. Check the electrode connections
2. The electrode should be filled with saturated potassium chloride. There should be a plastic squeeze bottle on the ledge behind the pH meter.
3. To add more KCl, open the filling hole at the top of the electrode, press the spout of the KCl bottle into the hold and squeeze the bottle (do this over the sink). The KCl level should be ~ 1/4-inch from the top. Rinse any excess KCl off the outside of the electrode.
4. When not in use, store the electrode in pH 7 buffer or KCl solution, leaving the filling hole open to avoid back filling the electrode with storage solution.