PH meter PH electrode standard buffer mixing ratio
pH electrode, also known as pH probe, pH sensor, English name pH electrode or pH sensor, is the part of the PH meter in contact with the measured substance, used to measure the electrode potential device.
PH meter PH electrode together with the need to correct the instrument with a standard buffer, and in the configuration of the configuration of the standard cache material, you need to deploy a standard buffer ratio to ensure the accuracy of the measurement. Here we come to understand the PH meter PH electrode calibration of the standard buffer blending ratio:
(1) Potassium oxalate standard buffer Precision weighing in 54 ± 3 ℃ dry 4 ~ 5 hours of potassium oxalate [KH3 (C2O4) 2-2H2O] 12.61g, add water to make soluble and dilute to 1000ml.
(2) Potassium hydrogen phthalate standard buffer Precision weighing of potassium hydrogen phthalate [KHC8H4O4] 10.12g dried at 115 ± 5 ℃ for 2 ~ 3 hours, add water to dissolve and dilute to 1000ml.
(3) Phosphate standard buffer (pH 6.8) Precision weighing of anhydrous disodium hydrogen phosphate 3.533g dried at 115 ± 5 ℃ for 2 ~ 3 hours and potassium dihydrogen phosphate 3.387g, add water to dissolve and dilute to 1000ml.
(4) phosphate standard buffer (pH 7.4) Precision weighing in 115 ± 5 ℃ dry 2 ~ 3 hours of anhydrous disodium hydrogen phosphate 4.303g and potassium dihydrogen phosphate 1.179g, add water to dissolve and dilute to 1000ml.
(5) Borax standard buffer Precision weighing borax [Na2B4O7-10H2O] 3.80g (Note: avoid weathering), add water to dissolve and dilute to 1000ml, placed in polyethylene plastic bottles, tightly corked, avoid contact with carbon dioxide in the air.
