Ph Values At Various Temperatures; Electrode Conditioning And Maintenance . 105 - Hanna Instruments HI 504 Instruction Manual

pH VALUES AT VARIOUS TEMPERATURES

Temperature has a significant effect on pH. The calibration
buffer solutions are effected by temperature changes to a lesser
degree than normal solutions.
For manual temperature calibration please refer to the fol-
lowing chart:
TEMP
°C
0
5
10
15
20
25
30
35
40
45
50
55
60
65
70
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.
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pH VALUES
°F 4.01 6.86 7.01 9.18 10.01
32 4.01 6.98 7.13 9.46 10.32
41 4.00 6.95 7.10 9.39 10.24
50 4.00 6.92 7.07 9.33 10.18
59 4.00 6.90 7.04 9.27 10.12
68 4.00 6.88 7.03 9.22 10.06
77 4.01 6.86 7.01 9.18 10.01
86 4.02 6.85 7.00 9.14 9.96
95 4.03 6.84 6.99 9.10 9.92
104 4.04 6.84 6.98 9.07 9.88
113 4.05 6.83 6.98 9.04 9.85
122 4.06 6.83 6.98 9.01 9.82
131 4.07 6.84 6.98 8.99 9.79
140 4.09 6.84 6.98 8.97 9.77
149 4.11 6.85 6.99 8.95 9.76
158 4.12 6.85 6.99 8.93 9.75
ELECTRODE CONDITIONING AND MAINTENANCE
PREPARATION
Remove the electrode protective cap.
DO NOT BE ALARMED IF ANY SALT DEPOSITS ARE
PRESENT.
This is normal with electrodes and they will disappear when
rinsed with water.
During transport tiny bubbles of air may have formed inside
the glass bulb. The electrode cannot function properly under
these conditions. These bubbles can be removed by "shaking
down" the electrode as you would do with a glass thermom-
eter.
If the bulb and/or junction are dry, soak the electrode in
HI 70300 Storage Solution for at least one hour.
If the electrode does not respond to pH changes, the battery
may be run down and should be replaced.
TEST MEASUREMENT
Rinse the electrode tip with distilled water.
Immerse the tip (bottom 4 cm / 1½") in the sample and stir
gently for approx. 30 seconds.
For a faster response and to avoid cross contamination of
the samples, rinse the electrode tip with the solution to be
tested, before taking your measurements.
STORAGE
To minimize clogging and assure a quick response time, the
glass bulb and the junction should be kept moist and not
allowed to dry out. This can be achieved by installing the
electrode in such a way that it is constantly in a well filled with
the sample (stream or tank).
When not in use, replace the solution in the protective cap
with a few drops of HI 70300 Storage Solution or, in its
absence, HI 7082 KCl 3.5M Solution.
Follow the Preparation Procedure above before taking mea-
surements.
Note
NEVER STORE THE ELECTRODE IN DISTILLED OR DEION-
IZED WATER.
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