User Guide

3534
After entering the calibration date,
press CFM and the meter will
return to the normal operating
mode.
Note: during calibration, the
secondary LCD displays
the selected buffer
value. By pressing
RANGE the tempera-
ture value can be also
displayed. This will allow you to check
the buffer temperature during calibration.
TWO-POINT CALIBRATION
A two-point calibration is recommended for
best accuracy. As a first point use pH 7.01
(or pH 6.86 can also be used for pH 301). As
a second point use pH 4.01 (or pH1.68 for
pH 301 only) if you are going to measure acid
samples (pH 7 or less), use pH 10.01 (or
pH 9.18 for pH301 only) if you are going to
measure alkaline samples.
• Proceed as described above
for one point calibration but
do not quit calibration by
pressing CAL at the end.
• After the first calibration
point is confirmed, immerse
the pH electrode into the
second buffer solution (pH
4.01 or pH10.01; for pH301
only, the second buffer can
also be pH 1.68 or pH 9.18) and shake
briefly.
Note: the electrode should
be submerged ap-
proximately 4 cm
(1½") into the solu-
tion. The temperature
probe should be located as close
as possible to the pH electrode.
CFM/
RANGE
RANGE
CAL
HI 7004
4 cm
(1
½
")
(and adjusts the offset point).
The buffer value is
then displayed on
the primary LCD and
the secondary LCD
will display the ex-
pected second buffer value.
For pH 302 only: the printer will print
further instructions for the calibration pro-
cedure.
• Press CAL and the calibra-
tion process is ended with
just the offset of the meter
calibrated. For best accuracy
however, it is recommended
that a two-point calibration is
performed.
For pH 300 only :
The calibration process
is complete and the dis-
play will ask for the date
entry.
Use UP or DOWN to
select the month, the
day and the year.
Use CAL to toggle between
month, day and year.
2
pH
pH
CAL
BUF
Now dip the e-
lectrode in 2nd
solution, wait
30 sec and then
press CFM
CAL
DATE
CAL
°C °C
CAL