10
corresponding to the temperature of the buffer 7.00pH or 6.86pH as
measured in 1.2.
Refer to Table 1. If the reading still drifts, repeat 1.3 until a stable reading
is obtained.
If Er1 is displayed, check to make sure that the correct buffer is used and
that the electrode offset is less than +/- 1.5pH. Replace the buffer and/or
the pH electrode. Press the CLEAR key and repeat from 1.2. Er1 may
appear if the STAND/STAND I key is pressed before the electrode and
ATC/Temp probe settle to /- 1.5pH of the buffer value. Allow
sufficient time for the electrode and ATC/Temp probe to stabilize before
taking any action.
If Er4 is display, The buffer temperature is out of the 0 to 50.0 degree C
range. Bring the buffer temperature within range and repeat 1.2. It is not
necessary to press the CLEAR key.
1.4 Remove the pH electrode and ATC/Temp probe from buffer 7.00pH or
buffer 6.86pH, rinse with distilled water and immerse in buffer
4.01pH, 10.01pH (model 6250/model 6219) or buffer 4.00pH, 9.18pH
(model 6250C/ model 6219C). The instrument will display the
temperature of the second buffer.
1.5 Allow sufficient time for the pH electrode and ATC/Temp probe to
stabilize. Press the SLOPE/STAND II key. The SLOPE indication
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 1.4. Refer to Table 1. If reading still drifts, repeat 1.5 until a
stable reading is obtained. The micro computer inside the instrument will
calculate and compensate for the pH electrode slope deviation
corresponding to the values of the two calibration buffers. The instrument
is dual point calibrated and is ready for measurements.
If Er2 is display, check to make sure that the correct buffer is used and that
the slope of the electrode is not off by more than +/- 30% from the
theoretical slope. Replace the buffer and/or the pH electrode. Press
