9
12.4 Never test oily liquids.
12.5 Make sure the battery cap is completely closed with the O-ring. Otherwise, the
waterproof rating could be compromised.
13 Troubleshooting Guide
Trouble
Reason
How to fix
Cannot calibrate
Incorrect calibration
order
Power on the tester, calibrate pH 7 first, then pH 4.
After pH 4 is calibrated, if you want to calibrate pH 7
again, you need to reboot the tester.
Poor quality standard
solutions
Replace with fresh and clean standard calibration
solutions made by legitimate scientific instrument
manufacturers.
Contaminated probe
Clean the probe with
Apera’s cleaning solution or
detergent water.
Aged probe
Replace the probe.
Dried-out probe
Soak the probe in the 3M KCL soaking solution for at
least 1 hour.
Probe is not fully
submerged in the
solution
Make sure the probe is fully immersed in the solution at
least 1 inch deep.
Air bubbles around the
sensor
Make a quick stir in the solution to remove air bubbles.
Reading is always
slowly changing,
won’t stabilize
.
Contaminated probe
Clean the probe with
Apera’s cleaning solution or
detergent water.
Clogged junction
Clean the probe with
Apera’s cleaning solution, then
soak it in 3M KCL soaking solution overnight.
Aged probe
Replace the probe.
Testing pH of low iconic
strength solutions like
tap water, drinking
water, RO water
Be patient, wait for 2-5 minutes to reach a fully
stabilized reading. If still not stabilizing, add 1ml of 3M
KCL solution to 1000ml of test solution.
Display similar
readings in any
solutions or
always display 7.0
pH
Broken probe
If you
don’t find any visible damage of the probe and it’s
within the 1-year probe warranty, contact your point of
purchase for warranty fulfillment;
If there is visible
damage or the probe is more than 1-year old, replace
the probe.
Reading keeps
jumping
Probe is not fully
submerged in the
solution
Make sure the probe is fully immersed in the solution at
least 1 inch deep.
Air bubbles around the
sensor
Make a quick stir in the solution to remove air bubbles.
Probe is not properly
connected, or the pin
connector is broken.
Check the
probe’s connector, make sure it’s not broken
and is correctly connected. Align the probe and
instrument correctly before plugging in.
Never force it.
Ensure that the probe connector is not exposed in the
air too long.