User Guide

9
8
HI 7007
RINSE
HI 7007
CALIBRATION
HI 7004 HI 7007
H
I 7
0
0
4
IMPORTANT
The instrument's pH range should be re-calibrated:
When the meter is new.
Whenever the pH electrode is replaced.
At least once a month.
After use in aggressive chemicals.
After cleaning procedure and changing the reference electrolyte.
For greatest accuracy.
INITIAL PREPARATION
Pour small quantities (up to 4cm / 1½" level)
of pH 7.01 (HI7007 or HI8007) and pH4.01
(HI7004 or HI8004) or pH 10.01 (HI7010 or
HI8010) solution into clean beakers. If pos-
sible use plastic beakers to minimize any EMC
interferences.
If you are measuring in the acid range, use pH4.01 as second buffer;
if you are measuring in the alkaline range, use pH10.01 as second
buffer.
For accurate calibration, use two bea-
kers for each buffer solution; the first
for rinsing the electrode, the second
for calibration. In this way, contami-
nation of the buffer is minimized.
Note: the electrode should be submerged approximately 4 cm (1½")
into the solution.
PROCEDURE
Note: If you need to calibrate to NBS standards, use pH 6.86 (HI7006
or HI8006) and pH 9.18 (HI7009 or HI8009) instead of
pH7.01 and 10.01 respectively.
Use a ChecktempC or a glass thermometer as reference thermometer.
Switch the instrument on by pressing the ON/OFF switch.
Rinse and immerse the pH electrode in pH 7.01
buffer and shake briefly. Wait 1 or 2 minutes for
the reading to stabilize.
pp
pp
p
H CALIBRATIONH CALIBRATION
H CALIBRATIONH CALIBRATION
H CALIBRATION
Note the temperature of the buffer solution using a
ChecktempC or a glass thermometer (e.g.20C).
Press the C key to select temperature setting.
Adjust the Temperature knob until the LCD shows the noted tem-
perature.
Press the pH key to select pH measurement.
Wait 1-2 minutes and adjust the OFFSET knob until display shows
the pH value at the noted temperature (see the pH versus tem-
perature chart).
Rinse and immerse the pH electrode in pH 4.01/pH 10.01 buffer
and shake briefly.
Wait 1-2 minutes and adjust the SLOPE knob until display shows
the pH value at the noted temperature (see the pH versus tem-
perature chart).
The pH calibration is now complete.
4 cm
(1½
")