9
4.3.2. The 2
nd
point calibration
Press key to enter into the calibration mode, CAL 2 blinks at the top right of LCD, indicating make the 2
nd
point calibration. Rinse pH electrode in pure water, allow it to dry, 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 displays on LCD. Press key to calibrate the meter.
electrode slope of acidity range display after calibration is done, the 2
nd
point calibration finished, meter goes
to measurement mode, the bottom left of LCD indicating .
4.3.3. The 3
rd
point calibration
Press key to enter into the calibration mode, CAL 3 blinks at the top right of LCD indicating make the 3
rd
point calibration. rinse pH electrode in pure water, allow it to dry, submerge it in pH10.01 buffer solution, Stir
the solution briefly and allow it to stay in the buffer solution until the reading is stabilized. 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 displays on LCD. Press key to calibrate the meter. Electrode
slope of acidity range display after calibration is done. After the 3
rd
point calibration is completed, meter goes
to measurement mode, the bottom left of LCD indicating .
Notes:
(a) The meter can perform 1-3 points calibration. When the 1
st
point calibration is done, meter goes to
measurement mode under 1
st
point calibration mode. Same procedure as 2
nd
point calibration and 3
rd
point calibration.
(b) During calibration process, if a stable reading has not been reached, no displays on
LCD, press key, Er2 will displays on LCD, See Chart
–
6
(c) In calibration mode, press key to exit.
4.4. Customer-defined calibration (take 1.60 pH and 6.50 pH calibration solution as an example)
4.4.1. Select
CUS
from parameter setting P1.1 (please refer to clause 7.3 for customer-defined solution). The
meter enters into Customer-defined calibration mode.
4.4.2. Rinse pH electrode in pure water, allow it to dry, and submerge it in pH1.60 buffer solution. Stir the
solution briefly and allow it to stay in the buffer solution until a stable reading is reached. When LCD displays
the stable measuring value and icon, press key and the measuring value flashes.
CAL1
blinks at the top right of LCD, indicating 1
st
point calibration of customer-defined solution. Press
key or key to adjust the measuring value to 1.60, then press key to calibrate the meter. After
calibration is done, meter goes to measurement mode.
4.4.3. Rinse pH electrode in pure water, allow it to dry, and submerge it in pH 6.50 buffer solution. Stir the
solution briefly and allow it to stay in the buffer solution until a stable reading is reached. When LCD displays
the stable measuring value and icon, press key and the measuring value flashes.
CAL 2
blinks at
the top right of LCD, indicating 2
nd
point calibration of customer-defined solution, Press key or key to
adjust the measurement value to 6.50, then press key to calibrate the meter. After calibration is done,
the meter returns to the measurement mode.