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Before You Begin:

Remove electrode cap. To condition electrode, immerse electrode in electrode storage solution, buffer or tap water for at least 30 minutes. Do Not use de-ionized water.

Calibration should be done regularly, typically every day that the Tester is used. You can calibrate at up to three points (ph 4,7, an 10).

1. Press on/off button to switch unit on.
2. Dip electrode 1/2 to 1” into chosen buffer (ph 4,7, or 10).
3. Press CAL button to enter Calibrate (CA) mode. ‘CA’ Flashes on the display. Then, a pH value close to the pH buffer value will flash repeatedly.
4. After at least 30 seconds (about 30 flashes) press the hold/con button to confirm calibration. The display will show ‘CO’ and then switch to the buffer value reading.
5. Repeat with other buffers if necessary. Rinse electrode in tap water before dipping into next buffer.

Calibration troubleshooting:
Failure to press hold/con to confirm calibration (step 4 above). Pressing the CAL button will resume measuring mode but will not enter the calibration value.

Insufficient sampling time. If the Tester does not have a long enough exposure to the buffer, a stable calibration point will not be reached. Wait at least 30 seconds before pressing Hold/Con.

Failure to rehydrate the electrode. A dry electrode will give fluctuating readings while it re-hydrates in a buffer, causing errors.

pH Testing:

1. Remove cap from the electrode and press the on/off button to switch Tester on.
2. Dip the electrode 1/2 to 1” into the test solution. Stir once and let the reading stabilize.
3. Note the pH or press Hold/Con button to freeze the reading. Press Hold/Con again to release the reading.
4. Press on/off to turn off Tester. If you do not press a button for 8.5 minutes the Tester will automatically shut off to conserve batteries.

Instrument Maintenance:

  • Rinse the electrode with tap water or electrode storage solution after each measurement.
  • In aggressive chemicals, dirty or viscous solution, and solutions with heavy metals or proteins, take readings quickly and rinse electrode immediately afterward.
  • Periodic soaks in warm pH 4 buffer will help remove contaminants.
  • If possible, keep a small piece of paper or sponge in the electrode cap- moistened with clean water or electrode storage solution (not de-ionized water)- and close the cap over the electrode.

Note: Tester life is dependent on meter and electrode care. If the electrode is exposed to materials that contaminate the reference junction, electrode life will be shortened.

When you need a new electrode, see “Electrode Replacement” on insert in back of box – follow link to order online.