User Guide

21
For greatest accuracy, it is recommended
that the instrument is calibrated frequently.
For a faster operation, it is possible to stan-
dardize the electrode at pH 7.01 only (one
point calibration), but it is always good prac-
tice to calibrate at least 2 points.
The standard calibration program of the meter,
however, is prepared for 3 (maximum) buffers.
There is a choice of 5 memorized standard
buffers:
1
st
buffer (offset) pH 6.86 or 7.01
2
nd
buffer (1
st
slope) pH 4.01
3
rd
buffer (2
nd
slope) pH 9.18 or 10.01
The calibration sequence values of the 2
nd
and 3
rd
buffers can be reversed.
Due to electrode conditioning time the elec-
trode must be kept immersed in the sample
for a few seconds to stabilize. The user will
be guided step by step with easy indications
on the display during the pH calibration. This
will make the calibration a simple and error-
free procedure.
INITIAL PREPARATION
Pour small quantities of:
• pH 7.01 (HI7007/HI8007) or
pH 6.86 (HI7006/HI8006)
• pH 4.01 (HI7004/HI8004) or
• pH 10.01 (HI7010/HI8010) or pH 9.18
(HI7009/HI8009) solution into individual bea-
kers.
If possible, use plastic
beakers to minimize any
EMC interferences. For
accurate calibration use
two beakers for each
pH CALIBRATION
HI 7007
CALIBRATION
HI 7007
RINSE
HI 7004 HI 7007
H
I
7
0
0
4