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INW - TempHion Instruction Manual
Appendix B1: pH Field Calibration Temperature Chart
The pH of any buffer varies slightly with temperature change. For this reason, it is
important that you determine the current pH value of the buffer you are using during
calibration. From this chart, determine the pH value at your current buffer temperature
and use this value as the “Ref pH” value in the Settings and Calibration window. For
example, if you are using a pH buffer of 7 and your buffer temperature is 20 degrees C,
then you would enter 7.02 in the Ref pH box.
Appendix B2: M & I Range for pH Calibration
There are three variations of TempHion pH confi guration. Depending on which way
yours is confi gured, your M and I values should be between those values shown in the
chart below when you calibrate the sensor.
To determine which confi guration you have, you will need to create a short data fi le,
then retrieve and export the data – it doesn’t matter whether the sensor is deployed, or
in a buffer, or just in air for this. Once you have exported your data fi le, open it in Excel
and note the P and H values for the pH channel.
• If P = 2.97 and H = 0.567, this is the preferred confi guration for all but the
wastewater pH sensors.
• If P = -2.389 and H = -0.29, this is an older confi guration. This can still be used, but
if you need higher accuracy, contact INW for instructions on how to reconfi gure.
• If P = 6.76 and H = 0.567, this is a wastewater pH sensor, without a reference
solution reservoir.
Calibration Temperature
pH 4.00
pH 7.00
pH 10.00
°
C
°
F
10
50
4.00
7.07
10.19
15
59
4.00
7.05
10.12
20
68
4.00
7.02
10.06
25
77
4.00
7.00
10.00
30
86
4.02
6.99
9.94
35
95
4.02
6.98
9.90
40
104
4.04
6.97
9.85
45
113
4.05
6.97
9.82
50
122
4.06
6.97
9.78