23
(1½") into the solution. For HI 9110 and
HI 9210, place the thermometer close
to the pH electrode.
• Adjust the OFFSET trimmer (#3 pages 9-
10) until the LCD shows the pH value at
the buffer temperature (see page 24 for pH values at various
temperatures). With HI 9210N, press RANGE to read the buffer
temperature.
• Rinse first with clean or distilled water and then with a small
amount of the next buffer (2
nd
calibration point). Dip the
electrode into pH 4.01 (or 10.01) buffer, stir gently and wait
until the display has stabilized.
• Adjust the SLOPE trimmer (#4 pages 9-10) until the LCD
displays the pH value at the second buffer temperature (see
page 24).
• pH calibration is now complete. Once the calibration process is
complete, replace the trimmer cover and tighten it to ensure a
proper seal against water and humidity ingress.
pH
HI 7004
24
Temperature has an effect on pH. The calibration buffer solutions are
affected by temperature changes to a lesser degree than normal
solutions.
For manual temperature calibration (standard with HI 9110 and
HI 9210 or optional with HI 9023C, HI 9024C and HI 9025C)
please refer to the following chart.
For instance, if the buffer temperature is 25 C, the display should
show pH 4.01, 7.01 or 10.01 at pH 4, 7 or 10 buffers, respectively.
At 20 C, the display should show pH 4.00, 7.03 or 10.06. The
meter reading at 50 C will then be 4.06, 6.98 or 9.82.
pp
pp
p
H VALUES AT VARIOUSH VALUES AT VARIOUS
H VALUES AT VARIOUSH VALUES AT VARIOUS
H VALUES AT VARIOUS
TEMPERATURESTEMPERATURES
TEMPERATURESTEMPERATURES
TEMPERATURES
TEMP pH VALUES
°C °F 4.01 6.86 7.01 9.18 10.01
0
5
10
15
20
25
30
35
40
45
50
55
60
65
70
32
41
50
59
68
77
86
95
104
113
122
131
140
149
158
4.01
4.00
4.00
4.00
4.00
4.01
4.02
4.03
4.04
4.05
4.06
4.07
4.09
4.11
4.12
6.98
6.95
6.92
6.90
6.88
6.86
6.85
6.84
6.84
6.83
6.83
6.84
6.84
6.85
6.85
7.13
7.10
7.07
7.04
7.03
7.01
7.00
6.99
6.98
6.98
6.98
6.98
6.98
6.99
6.99
9.46
9.39
9.33
9.27
9.22
9.18
9.14
9.10
9.07
9.04
9.01
8.99
8.97
8.95
8.93
10.32
10.24
10.18
10.12
10.06
10.01
9.96
9.92
9.88
9.85
9.82
9.79
9.77
9.76
9.75
