14
is completed and the instrument is ready to be sloped at a
second buffer. The instrument will display the buffer value
corresponding to the temperature of the buffer 7.00 (or 6.86)
as measured in 3.2 (refer to table 1). If the reading still drifts,
repeat 3.3 until a stable reading is obtained.
If "
Er 1
" is displayed, check that the correct buffer is used
and that the electrode offset is greater than - 1.5 and less
than +1.5 pH. Replace the buffer and/or the pH electrode.
Press the [CLEAR] key and repeat from 3.1. "
Er 1
" may
appear if the [STAND] key is pressed before the electrode
and ATC/Temp probe settle to within ±1.5 pH 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 with in the
range . and repeat 3.2 It is not necessary to press the
[CLEAR] key.
3.4 Remove the pH electrode and ATC/Temp probe from
buffer 7.00
(or 6.86). Rinse them in distilled water and immerse in
buffer 4.01 or 9.18 or 10.01. The instrument will display the
temperature of the second buffer.
3.5 Allow sufficient time for the pH electrode and ATC/Temp
probe
to stabilize. Press the [SLOPE] key. The SLOPE annunciator
will stop flashing and stay on. The instrument will display
the second buffer value corresponding to the temperature of
the second buffer, as measured in 3.4 (refer to table 1). If the
reading still drifts, repeat 3.5, until a stable reading is
obtained. The instrument will calculate and compensate for
the pH electrode slope deviation corresponding to the
