9
mode
3. Ion values out of the 0 to 119.8 conc. range when in ion mode
OPERATIONAL PROCEDURES
pH CALIBRATION
Connect the AC adaptor to the AC power line. Make sure the correct AC
adaptor is used. It is recommended to conserve the internal batteries by
using AC power whenever it is available. Turn on the instrument by
pressing the ON/OFF (model 6250)/ POWER (model 6219) key. The
instrument will enter into the state when the instrument was last turned off.
It is not necessary to press the CLEAR key. You also can press RESOL.
key to select the optimum resolution you need.
1. Calibration with ATC/Temp probe in the pH mode.
A triaxle 3-in-1 pH/Ref/Temp electrode with user's electrode cable, can be
used in place of a combination pH electrode and a separate ATC/Temp
probe.
1.1 Connect the pH electrode and the ATC/Temp to the connectors of the
instrument. Refer to the Figure 2. The ATC annicator (model 6250)/ green
color ATC LED lamp (model 6219) will be on. Press the MODE key to
enter into pH mode, the pH anniciator (model 6250) or pH LED
lamp (model6219) will on and the STAND anniciator (model 6250) or
green color STAND LED (model 6219) will flash.
1.2 Rinse the pH electrode and ATC/Temp probe in distilled water and
immerse in pH 7.00 (model 6250/6219) or pH 6.86 (model 6250C/6219C).
The instrument will display the buffer temperature.
1.3 Allow sufficient time for the electrode and ATC/Temp probe to
stabilize. Press the STAND/STAND I key. The STAND indication will
be on and the SLOPE annicator (model 6250) or SLOPE green
color LED lamp (model 6219) will flash, indicating that standardization at
buffer 7.00pH or 6.86pH is complete and the instrument is ready to be
sloped at a second buffer. The instrument will display the buffer value
