KROHNE OPTISENS ORP 8590 EN - Manual (Page 31)

APPENDIX
7
31
OPTISENS ORP 8590
www.krohne.com 01/2014 - 4001933801 MA OPTISENS ORP 8590 R01 en
7.2 ORP dependency
The output from a pH-electrode varies with the temperature in a predictable way. The size of the
variation depends on both the temperature and the pH being measured.
At pH 7 and 25°C / 77°F the temperature error is zero. If temperature or pH changes the
temperature error is calculated using the following formula:
0.03 pH-difference / pH or 0.03 pH-difference / K
° C ° F pH pH pH pH pH pH pH pH pH pH pH pH
5 41 2.30 3.24 4.18 5.12 6.06 7.00 8.06 9.12 10.18 11.24 12.30 13.36
15 59 2.15 3.12 4.09 5.06 6.03 7.00 8.03 9.06 10.09 11.12 12.15 13.18
25 77 2.00 3.00 4.00 5.00 6.00 7.00 8.00 9.00 10.00 11.00 12.00 13.00
35 95 1.85 2.88 3.91 4.94 5.97 7.00 7.97 8.94 9.91 10.88 11.85 12.82
45 113 1.70 2.76 3.82 4.88 5.94 7.00 7.94 8.88 9.82 10.76 11.70 12.64
55 131 1.55 2.64 3.73 4.82 5.91 7.00 7.91 88.2 9.73 10.64 11.55 12.46
65 149 1.40 2.52 3.64 4.76 5.88 7.00 7.88 8.76 9.64 10.52 11.40 12.28
75 167 1.25 2.40 3.55 4.70 5.85 7.00 7.85 8.70 9.55 10.40 11.25 12.10
85 185 1.10 2.28 3.46 4.64 5.82 7.00 7.82 8.64 9.46 10.28 11.10 11.92
95 203 0.95 2.16 3.37 4.58 5.79 7.00 7.79 8.58 9.37 10.16 10.95 11.74
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