PH value measurement method and PH tester performance characteristics analysis
Concept of pH The value of the hydrogen ion concentration index is commonly known as "pH". It is a value that indicates the degree of acidity or basicity of a solution, i.e., the negative of the common logarithm of the concentration of hydrogen ions contained.
Three methods for determining the pH of a solution:
1. Using a pH indicator. A pH indicator is added to the solution to be measured. Different indicators change colour according to different pH values, and the pH range can be determined from the study of the indicator. The pH range can be determined from the study of the indicator. When titrating, it can be used as a precise pH standard.
2. Use pH test paper. pH test paper has extensive test paper and precision test paper, dip a glass rod into the solution to be tested on the test paper, and then according to the colour change of the test paper against the 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 the hydrogen ions, but the oil does not contain the hydrogen ions, so the pH test paper can not show the pH of the oil. The oil does not contain hydrogen ions, so the pH paper will not show the pH of the oil.
3. Use a pH meter. pH meter is an instrument for determining the pH value of a solution by means of a pH-selective electrode (e.g., glass electrode). pH meter can be accurate to two decimal places.
Performance characteristics of pH tester:
● Chinese display, Chinese menu, Chinese notation: the whole operation steps are prompted in Chinese, which can be conveniently done without instruction manual.
●Multi-parameter display on the same screen: display pH value, input mV number (or output current), temperature, time and status on the same screen.
●History curve: automatically store the measurement data every 5 minutes, and can continuously store one month's pH value.
●Notebook function: the notebook faithfully records the operation and use of the instrument and the time of alarm occurrence, which is convenient for management.
●Monitoring electrode function: the way, time and result of each calibration are recorded, which is convenient for querying and analysing the change rule of electrode.
●Digital clock function: provide time reference for various functions.
●25℃ conversion: 25℃ reference temperature conversion for pure water and ammonia-added ultrapure water, realising the display of pH value at 25℃, especially suitable for the measurement of various water qualities in power plants.
●Stable instrument without crash: Watchdog programme ensures that the instrument will not crash in continuous operation.
●Manual current source function: the output current value can be checked and set arbitrarily, which is convenient for testing the recorder and the lower computer.
●Software setting current output mode: software selection is 0-10mA or 4-20mA output.
●Four calibration methods: manual input of zero E0, slope S and known pH value calibration are newly added to satisfy customers in various situations.
PH tester meter is widely used in industry, electric power, agriculture, medicine, food, scientific research and environmental protection. The instrument is also a necessary inspection equipment in food factories, drinking water factories to do QS, HACCP certification.
