Troubleshooting Guide - Hanna Instruments Edge Instruction Manual

Troubleshooting
Guide
Maintenance
82
Symptoms
Slow response/excessive
drift.
Readings fluctuate up
and down (noise).
The meter does not
accept the buffer/
standard solution for
calibration.
If the display shows: "pH"
and "-2.00" or "16.00"
blinking.
The display shows EC,
TDS or NaCl readings
blinking.
The display shows DO
reading blinking.
Problems
Dirty pH electrode.
pH: Clogged/dirty
junction. Low electrolyte
level (refillable
electrodes only).
EC: EC probe sleeve not
properly inserted; air
bubbles inside sleeve.
DO: DO probe electrolyte
contains entrapped gas.
pH: Dirty electrode or
contaminated buffer.
EC: The EC probe is
defective.
Out of range in the pH
scale.
Out of range in EC, TDS
or NaCl scale.
Out of range in DO scale.
Solution
Clean the electrode and then soak
the tip in HI 7061 or HI 8061 for 30
minutes.
Clean the electrode. Refill with fresh
solution (for refillable electrodes only).
Check cable and connectors.
Reinstall the sleeve. Tap the probe to
remove air bubbles. Move to center
of beaker. Verify top hole in sleeve is
covered with solution.
Remove cap. Refill, tap and reinstall.
Follow the cleaning procedure. If still
no results, replace the electrode.
Replace buffer.
Follow the cleaning procedure. If still
no results replace the probe. Verify
correct standard is selected.
A) Verify that the shipping cap has
been removed.
B) Make sure the pH sample is in the
specified range.
C) Check electrolyte level and general
state of the electrode.
Verify the plastic shipping spacer has
been removed from probe. Recalibrate
the probe. Make sure the solution is in
specified range. Make sure the range is
not locked. (Select Auto range)
Verify area of cathode is free of bubble
inside cap. Verify solution movement
past membrane. Remove cap, inspect
and clean if necessary. Install new
cap, fresh electrolyte with no bubbles,
permit longer polarization. Stir or
increase flow rate.