Reference Calomel Ag/AgCl (1 m) Ag/AgCl (3m) Ag/AgCl (verz.) pH glass
ORP BUFFER MEDIUM
Saturated in 1.68 pH 356 364 393 401 ± 50
Chinhydron in 4.0 pH 218 226 255 263 ± 50
in 6.86 pH 49 57 86 94 ± 50
in 9.18 pH -87 -79 -50 -42 ± 50
Saturated
Hydrochinon in 6.86 pH -50 -42 -13 -5 ± -50
ZoBell
solution 187 195 225 232
NOTE: all values at 25 °C and tolerance +/- 20 mV
9-6. Buffer values