Apera Instruments PH850, Руководство пользователя, Страница: 9 / 20

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4.3 pH Meter Calibration (with an example of 3-point calibration)
4.3.1. First point calibration
(a) Press key to enter the calibration mode, “ CAL 1 ”
flashes at the top right of LCD and “7.00 pH” flashes at the bottom right of
LCD, indicating using pH 7.00 buffer solution to make the 1
st
point calibration.
(b) Rinse pH electrode in distilled or deionized water, allow it to dry, and
submerge it in pH7.00 buffer solution. Stir the solution briefly and allow it to
stay in the buffer solution until a stable reading is reached. When stable icon
stays on LCD, press key to calibrate, then 1
st
point calibration is
finished, the meter enters in measurement mode of one-point calibration.
Calibration guide icon will display at the bottom left of LCD.
4.3.2. Second point calibration
Press key to enter the calibration mode, “ CAL 2 ” flashes at the top right
of LCD indicating to make the 2
nd
point calibration. Rinse pH electrode in
distilled or deionized water, allow it to dry, and submerge it in pH4.00 buffer
solution. Stir the solution briefly and allow it to stay in the buffer solution until
a stable reading is reached. The meter’s display will show scanning and
locking process of calibration buffer solution at the bottom right of LCD. When
the meter locks 4.00 pH, stable icon stays on LCD, press key to
calibrate the meter. LCD will display electrode slope of acidity range, then 2
nd
point calibration is finished, the meter enters measurement mode of two-point calibration. Calibration guide
icons will display at the bottom left of LCD.
4.3.3. Third point calibration
Press key to enter the calibration mode, “ CAL 3 ” flashes at the top right of LCD indicating to make the
3
rd
point calibration. Rinse pH electrode in distilled or deionized water, allow it to dry, and submerge it in
pH10.01 buffer solution. Stir the solution briefly and allow it to stay in the buffer solution until a stable
reading is reached. The meter’s display will show scanning and locking process of calibration buffer solution
at the bottom right of LCD. When the meter locks 10.01pH, stable icon stays on LCD, press the
key to calibrate the meter. LCD will display electrode slope of alkalinity range, then 3
rd
point calibration is
finished, the meter enters in measurement mode of three-point calibration.
Calibration guide icons will display at the bottom left of LCD.
Notes:
(a) The meter can perform 1-3 points calibration. When the 1
st
point calibration is done, the meter will enter
measurement mode of one-point calibration. Two-point and three-point calibration are in the same manner.
(b) During the calibration process, if measuring value is not stable yet (when does not stay on and the
key is pressed, then Er 2 will display. (See chart – 5). To solve the problem, simply wait for to
Diagram- 6