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Page 17
8. Selecting Buffers for Auto Buffer Recognition
The
MC-81
is factory set to automatically recognise pH4.00, pH6.88 and pH9.23
buffers. However, some users may prefer to use pH7.00 instead of pH6.88 and
pH10.00 instead of pH9.23. The following procedure describes how to set which
of these buffers are automatically recognised at calibration.
1.
Switch the meter
OFF
with the
key.
2.
Press and HOLD the
key while switching the meter back on.
3.
Release the
key when the message,
“Select Buffer
” is displayed.
4.
The display will now show the currently selected primary buffer.
Use the
or
keys to alternate between pH6.88 and pH7.00 buffers.
5.
Press the
key to save the primary buffer.
6.
The display will now show the currently selected high pH buffer.
Use the
or
keys to alternate between pH9.23 and pH10.00 buffers (the
display shows pH10.0 for the latter but this buffer is stored as pH10.00).
7.
Press the
key to save the high pH buffer.
8.
The buffer recognition setting is kept in memory when the meter is switched
off, even if the battery is removed. The buffers are re-set to pH6.88 and
pH9.23 during initialisation.
NOTE:
pH6.88 buffer is a DIN 19266 and NBS Primary-standard pH solution.
Its use is highly recommended for the most accurate possible results. If
pH7.00 buffer is used, ensure that it is manufactured to 0.01pH
accuracy. pH7.00 buffer has a buffer capacity less than half that of
pH6.88 buffer and is therefore much less stable.