11
After two point calibration, pressing and holding the
[MEA./EFF.]
key for about 5 seconds will display the new electrode
efficiency.
If "
Er 2
" is displayed, check that the correct buffer is used
and that the slope of the electrode is not off by more than
30% from the theoretical slope. Only buffers 4.01, 9.18 or
10.01 may be used for slope calibration. Replace the buffer
and/or the pH electrode. Press the [CLEAR] key and repeat
from 1.1. "Er 2" may appear if the [SLOPE] key is pressed
before the electrode and the ATC/Temp probe settle to
within 30% of the buffer value. Allow sufficient time for the
electrode and ATC/Temp probe to stabilize before taking
any action
If "
Er 3
" is displayed, the buffer temperature is out of the 0
to 60
℃
range. Bring the buffer temperature within the
range and repeat 1.2 It is not necessary to press the
[CLEAR] key.
2. Calibration with manual temperature compensation in the pH-
AUTOLOCK mode.
2.1 Connect the pH electrode to the top of the instrument. The
MAN annunciator will be on. Press the [MODE] key for the
LCD
to indicate pH and for the AUTO annunciator to be on .
2.2 Rinse the pH electrode in distilled water and immerse in
buffer
7.00 pH(or 6.86). Set the instrument to display the
temperature of the buffer by pressing the [
∆
] and [
∇
]
keys. The displayed temperature must be less than 60.
℃
2.3 Press the [STAND] key. the STAND annunciator will be on
and
