GB/T 6043-2009Method for determination of pH value of wood (English PDF)

2.1

Wood powder at room temperature, the pH of distilled water extracts.

3.1 Instrument

3.1.1 pH meter

0.01 accuracy, the instrument should have a temperature compensation system and prevent outside influence of the induced current.

3.1.1.1 composite electrode

Usually immersed in distilled water for storage.

3.1.1.2

When using a glass electrode and a reference electrode assembly into a composite electrode membrane glass electrode should be immersed in distilled water and stored in the reference electrode

Use extreme calomel electrode or a silver chloride electrode containing a saturated solution of potassium chloride, and save the reference electrode is immersed in a saturated solution of potassium chloride.

3.1.2 scales

accuracy 0.001g.

3.1.7

magnetic stirrer or a glass rod.

3.1.8

plant material chopper.

3.2 Drugs and reagents

3.2.1.1

analytical grade potassium hydrogen phthalate [KHC6H4 (COO) 2].

3.2.1.2

analytically pure potassium dihydrogen phosphate (KH2PO4).

3.2.1.3

analytically pure disodium hydrogen phosphate (Na2HPO4).

3.2.1.4

AR borax (Na2B4O7 · 10H2O).

3.2.1.5

analytically pure boric acid (H2BO3).

3.2.1.6

analytically pure citric acid (C4H2O7 · H2O).

3.2.2 carbon dioxide-free distilled water

Distilled water was boiled for 5min ~ 10min, and cooled to room temperature.

4.1 test material requirements

4.1.1

timber.