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3.3.2 Display measuring information
：
(a) While in the the measurement mode, long press (
＞
2s), meter will display the last stored
information, and the storage number and “RM” icon will appear in the lower right corner of the LCD,
and the complete measuring information. Again short press or
meter will in turn display all the measuring data, Hold or to quickly check the
measuring data.
(b) In the data displaying mode (there are “
RM
” and storage number in the upper right corner of
the LCD), press key to return to the measuring mode.
3.3.3. Clear the stored measuring information: In the data displaying mode, press the key for
5 seconds, LCD will appear
CLr
for 2 seconds. It means that all the storage has been eliminated,
and returns to measuring mode.
4
Fluoride concentration measurement
4.1
Preparation
4.1.1 Press key to start , connect F501 -fluoride ion electrode; the meter automatically
switches to the fluoride concentration measurement mode.
4.1.2 Hold to change fluoride concentration unit from mg/l, ppm to pX , release the button
after selection.
4.1.3 Activate the electrode in 19.00mg/L calibration solution for about 10-20 minutes (as long as
the smiley face icon stays stably on the screen) before calibration and measurement. (Please note
that the display value during activation is random).
4.2
Calibration (
mg/L for example)
4.2.1 Press , LCD displays " 0.19 mg/L ", and LCD top right corner
CAL
and the bottom
left
L
will be flashing, indicating that the meter has entered the 1th point calibration mode and the
calibration solution is 0.19 mg/l; Rinse the fluoride-ion electrode in distilled or deionized water and
shake off the excess water; dip the electrode into 0.19 mg/L calibration solution, stir gently and let
it stand still. When measuring value is stable and icon stays on screen , then
press key again,
End
and
19.0 mg/L
will be displayed after a few seconds. While LCD top
right corner
CAL
and bottom left corner
H
flashing, indicating the meter has entered the 2nd
calibration mode and the calibration solution is 19.00 mg/L.
4.2.2 Dry the fluoride-ion electrode with clean tissue paper, dip into 19.00 mg/L Calibration
solution, stir gently and and let it stand still, when the reading is stabile and stays on screen ,
then press , after a few seconds
End
shows up, indicating the end of calibration; LCD left
