7
9
Probe Replacement
•
Screw off the probe ring, unplug the old probe; plug in the new
probe (make sure to align the connector's position properly), and
screw on the probe ring.
Probes don’t last forever. Every probe will eventually age and fail even
if you don't use it that often. The typical service life of GroStar probes
is 18-24 months depending on the frequency of usage and how well you keep it clean and
properly stored.
We recommend replacing your probe at least every 18 months to ensure the best accuracy.
The nice thing about GroStar pens is that you can just buy a replacement probe instead of a
whole new tester.
10 Notes
10.1 Never store the probe in pure water such as tap water, RO water, distilled water,
deionized water, etc.
10.2 Never use your finger to touch the glass membrane or use other material to wipe it.
10.3 Avoid testing in high (>113°F/ 45°C) or low temperature (<41°F/ 5°C) solutions as it will
cause greater measurement error and damage to the probe. Test your samples and
perform calibration close to room temperature as much as possible.
10.4 Never test oily liquids.
10.5 Make sure the battery cap is completely closed with the O-ring. Otherwise, the
waterproof rating could be compromised.
11 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.
