11
CLEAR key and repeat from 2.2. Only buffer 4.01 and 10.01 (model 6250/
model 6219 only) or Buffer 4.00 and 9.18 (model 6250C/ model 6219C
only) may be used to slope the instrument. Er2 may appear if the SLOPE
key is
pressed before the electrode and ATC/Temp probe settle to /- 30%
of the buffer value. Allow sufficient time for the electrode and
ATC/Temp probe to stabilize before taking any action.
If ER4 is displayed, 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.
2. Calibration with manual temperature compensation in the pH mode
2.1 Connect the pH electrode to the instrument. Refer to Figure 2.
The MANUAL indication MAN (model 6250) or red color
MANUAL LED lamp will be on. (Per Figure 3) Press the
MODE key for the instrument enter into pH mode , the pH
indicator wil on and the STAND anniciator (model 6250) or green
color STAND LED lamp(Model 6219) will start flash (Per Figure 3).
2.2 Rinse the pH electrode in distilled water and immerse in buffer
7.00 (model 6250/ model 6219) or 6.86. (model 6250C/ model 6219C)
Set the instrument to display the temperature of the buffer 7.00
or 6.86 by pressing the UP or DOWN key.
2.3 Pressing the UP key will increase the temperature and the DOWN
key will decrease the temperature. The displayed temperature must be
within 0.0 to 50.0 defree C range.
2.4
Allow sufficient time for the electrode to stabilize. Press
STAND/STAND I key. The STAND indication will be on and the
SLOPE anniciator (model 6250) or green color SLOPE LED lamp
(model 6219) will flash, indicating that standardizaion at buffer
7.00 or 6.86 is complete 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 set in 2.2,
2.3. Refer to Table 1. If the reading still drifts, repeat 2.4 until a
stable reading is obtained.
If Er1 is display, check to make sure that the correct buffer is used and
