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2 ph temperature dependency, Appendix – KROHNE OPTISENS PH 9100 EN User Manual

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7

APPENDIX

46

OPTISENS PH 9100

www.krohne.com

09/2012 - 4002314801 - MA OPTISENS PH 9100 R02 en

7.2 pH temperature dependency

The output from a pH-sensor 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