Specifications

MI 611-211 – October 2005 3. Operation
24
NOTE
Values in Table 8 are based on NIST Primary Buffer Systems. pH values are at
25°C. Chemical formulas are as follows:
4.01 pH: 0.05 molar Potassium Hydrogen Phthalate
6.86 pH: 0.025 molar Potassium Dihydrogen Phosphate;
0.025 molar Disodium Hydrogen Phosphate
9.18 pH: 0.01 molar Sodium Tetraborate Decahydrate (Borax)
15 4.00 6.90 9.28
20 4.00 6.88 9.23
25 4.01 6.86 9.18
30 4.02 6.85 9.14
35 4.03 6.84 9.10
40 4.04 6.84 9.07
45 4.05 6.83 9.04
50 4.06 6.83 9.01
Table 8. NIST Buffer Tables (Continued)
Temperature
°
C
4.01 pH 6.86 pH 9.18 pH
pH Value pH Value pH Value