What method to measure the pH value?
1, using pH indicator
pH indicator is added to the solution to be tested, different indicators will change color according to different pH, according to the indicator research can determine the range of pH. Titration, can be made accurate pH standard.
2, using pH test paper
pH test paper has a wide range of test paper and precision test paper, dip a glass rod into the solution to be tested, and then according to the color change of the test paper control standard colorimetric card can get the pH of the solution. pH test paper can not show the pH of the oil, because the pH test paper to measure the pH of the solution to be tested with hydrogen ions, but the oil does not contain hydrogen ions, so the pH test paper can not show the pH of the oil.
3, the use of pH meter
pH meter is an instrument to determine the pH of the solution, which is determined by the pH selection electrode (such as glass electrode) to determine the pH of the solution. The pH meter can be accurate to two decimal places.