Apera Instruments PH60-MS Troubleshooting

Trouble
Cannot calibrate
Reading is always
slowly changing,
won't stabilize.
Reason
Incorrect standard solutions
Bad standard solutions
Contaminated probe
Aged probe
Dried-out probe
Probe is not fully submerged
in the solution
Air bubbles around the
sensor shield
Contaminated probe
Clogged junction
Aged probe
Testing purified water like
tap water, drinking water
and RO water
Testing low ion
concentration solutions e.g.
distilled water and deionized
water
How to fix
When powered on, calibrate pH 7 first, then
pH 4. After pH 4 is calibrated, if you want to
calibrate pH7 again, you need to power off
and restart the tester.
Replace with a new reliable buffer solution.
Clean the electrode, it is best to use a cleaning
solution.
Replace the electrode.
Soak in the soaking solution overnight.
Make sure the electrode is immersed in the
solution at least 3 cm.
Make a quick stir in the solution to remove air
bubbles.
Clean the electrode, it is best to use a cleaning
solution.
Clean the electrode with cleaning solution,
then soak it in 3M KCL storage solution
overnight.
Replace the electrode.
Be patient, wait for 2-5 minutes to fully
stabilize. If still not stabilizing, add in 1ml of
3M KCL solution to 1000ml of test solution.
Contact Apera for a specialized pH electrode
suitable for low ion concentration solutions.