Thermo Fisher Scientific EcoScan pH/Ion 5 & 6 - Manual (Page 9)

Instruction Manual pH 5/6 & Ion 5/6
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3. CALIBRATION
3.1 pH Calibration
The meter is capable of calibrating up to 3 points using USA or NIST (nSt) pH buffer
standards or 2 points with Low Ionic (Pb) pH buffer standard. All new calibration values
will automatically override existing data.
USA pH 4.01, 7.00 and 10.01
NIST pH 4.01, 6.86 and 9.18
Pb pH 4.10 and 6.97
It is recommended that you perform at least 2-point calibration at room temperature (25
o C) using standard buffers, starting with first buffer at pH 7.00 (USA), pH 6.86 (NIST) or
pH 6.97 (Pb) followed by other buffer values.
For a 1-point calibration, calibration should be performed with a pH buffer value closest
to the expected sample value being measured. Otherwise calibrating at pH 7.00, pH
6.86 or pH 6.97 is advisable.
The meter has automatic buffer recognition that identifies the correct pH buffer values
during calibration. If non-standard pH buffers other than the above standards are used,
or the electrode has worn out, the LCD will flash “Er1”. Press the CAL key to abort
calibration and resume measurement. In general all pH buffer values have the window
of up to +/- 1 pH tolerance during calibration.
Ensure that you use new pH buffer solutions or sachets during calibration. Do not reuse
buffer solutions as it may be contaminated and affect the calibration and accuracy of
measurements. Always store buffer solutions in a dry, cool environment if possible.
Before use, remove the plastic protective cap of pH electrode and condition the glass
bulb by soaking it in tap water for 1-2 hours. This hydrates the glass bulb if electrode is
too dry or has not been used for a long period of time. Always rinse the probes with tap
water or rinse solution before and after each calibration/sample measurement to avoid
cross-contamination. For details refer to section 5 on Electrode care and maintenance.