OPERATION MANUAL
3
3. Operation
Preparation
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Insert the adapter into the 220V AC power supply; after that, insert the dc output plug
into "DC9V" socket. Screw off the short circuit plug of the meter, Screw on the pH
electrode. Please keep clean and dry of electrode before using, avoid to be polluted.
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Switch on the instrument and preheat for 5 minutes.
Calibration
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Before measurement, the instrument should be calibrated. To be accurate, the
calibration should be conducted by using the standard solution of pH4.00, 6.86, and
9.18.
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Connect power, and press on/off key to turn on the instrument.
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Make sure the pH combination electrode is screwed on, the sensor should be
cleaned by purified water and no remained water.
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Measure the temperature of pH buffer solution by thermometer; then, press the key
of “
∧
” or “
∨
” to adjust the temperature to be same as the buffer solution.
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Point calibration: Immerse the pH electrode into pH6.86 solution, shake it for a while,
then wait until the number shows on the screen is stable, keep pressing the
"calibration" key until the screen show the "CAL", first “6.86” twinkles, few seconds
later shows the: “END”, then shows the calibrated pH value. It indicates that the
calibration is completed and stored. Please note the final calibrated pH value shows
on the screen may be different under different temperature. For example, it will show
pH6.86 under 25
℃
and pH6.90 under 15
℃
. Details please find it from the last page.
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Slope calibration I: Take out the pH electrode, clean it by purified water and make it
dry, immerse the pH electrode into PH4.00 solution, shake it for a while then wait until
the number shows on the screen is stable, keep pressing the "calibration" key until
the screen show the "CAL", it shows 4.00 first, few seconds later shows the "END",
then shows the final pH value, which indicates the calibration is completed and be
stored. When finish calibration, the slope percentage will be adjusted automatically.
Please note the final calibrated pH value shows on the screen may be different under
