BOQU PHS-1701, User Manual, Page: 8 / 21

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slope (-59.16mV/pH) will be adopted. Press “Cal” for a long while, meter will
display slope and zero point, and then return to measurement interface.
2.1.3 Two point calibration
First step
Press one point calibration according to 2.1.2.1
。
(After the instrument's automatic end point or manual end point, do not press the
"Read" key, otherwise it will return to the measurement state)
Second step Wash electrode with distilled water
。
Third step Put electrode in the second buffer solution, and pree “Cal” start the
second point calibration.
After the signal is stabilized, the instrument will automatically end according to
the preselected end point or press the "reading" key.
。
Fourth step Pls see 2.1.2.2
2.1.4 Three point calibration
Process three point calibration according to 2.1.3.
Note
：
It is recommended to use a temperature probe or an sensor with a built-in
temperature sensor. If the MTC (manual temperature compensation) mode is used,
all buffers and sample solutions should be kept at the same set temperature.
In order to ensure accurate pH readings, calibration should be performed
periodically.
。