Hach PHC281, User Manual

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Section 7 Verify the calibration
Measure the pH value of a fresh pH buffer solution to make sure the result is accurate. The meter
compares the selected pH buffer value to the measured pH value and accepts or rejects the
measurement. The user can change the pH buffer solution and acceptance criteria for verification in
the probe-specific settings.
Note: Password protection may prevent access to the acceptance criteria.
7.1 Verification procedure
1. Go to the
verification menu.
The display shows
the pH buffer
solution to use for
verification.
Note: Menu name for
HQd meters: Run check
standard.
2. Prepare or pour
the pH buffer
solution into a
beaker.
3. Open the filling
hole.
4. Rinse the probe
with deionized water.
Dry the probe with a
lint-free cloth.
5. Put the probe in
the pH buffer
solution with the
sensor and
reference junction
fully in the solution.
Do not put the probe
on the bottom or
sides of the beaker.
6. Shake the probe
from side to side to
refresh the reference
junction and remove
air bubbles.
7. Stir gently, then
read the pH value of
the buffer solution.
The meter accepts
or rejects the result.
10 English