User Guide

14
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.
Due to electrode conditioning time the elec-
trode must be kept immersed in the sample
for a few seconds to stabilize. The meters
are equipped with a stability indicator and the
user will be guided step by step with easy
indications on the display during the pH cali-
bration. This will make the calibration a simple
and error-free procedure.
INITIAL PREPARATION
Pour small quantities of
pH 7.01 (HI7007/HI8007) and
pH 4.01 (HI7004/HI8004) and/
or pH 10.01 (HI7010/HI8010) solution into in-
dividual beakers. If possible, use plastic bea-
kers to minimize any EMC interferences.
For accurate calibra-
tion use two beakers
for each buffer solu-
tion, the first one for
rinsing the electrode,
the second one for calibration. By doing this,
contamination between the buffers is mini-
mized.
To get accurate readings, use pH 7.01 and
pH 4.01 if you are going to measure acid
samples, or pH 7.01 and pH 10.01 for alka-
line measurements or perform a 3-point cali-
bration for the entire range.
pH CALIBRATION PROCEDURE
HI 7004 HI 7007
H
I 7
0
0
4
HI 7007
CALIBRATION
HI 7007
RINSE