The three main structural parts of a pH meter
The pH meter consists of three main components Industry professionals know that pH acidimeter is a commonly used instrument and equipment. With the rapid development of the economy, its application scope and technology are constantly expanding and updating. Various pH meters and pH acidimeter products are used to accurately measure the pH value of liquid media, including industrial processing, food industry measurement, etc. PH meters can also measure the ion electrode potential MV value when equipped with corresponding ion selective electrodes. Using a pH meter and an acidity meter for potential measurement is a relatively precise method for measuring pH, widely used in industries, agriculture, scientific research, environmental protection, and other fields For first-time users of pH meters, let's take a look at the three main structural components of pH meters.
1. A current meter that can measure small potential differences in circuits with high resistance.
2. A glass electrode whose potential depends on the pH of the surrounding solution;
3. A reference electrode;
The following are separate explanations of the main functions of each component:
1. The function of an ammeter is to amplify the potential of the primary battery several times, and the amplified signal is displayed through the ammeter. The degree of deflection of the ammeter pointer indicates the strength of the signal it pushes. For practical use, the pH ammeter dial is engraved with the corresponding pH value; The digital pH meter directly displays the pH value in numbers.
2. The function of a glass electrode is to establish a potential difference that reacts to changes in the hydrogen ion activity of the measured solution. By placing the pH sensitive electrode and the reference electrode in the same solution, a primary cell is formed, whose potential is the algebraic sum of the potentials of the glass electrode and the reference electrode. E-battery=E-reference+E-glass. If the temperature is constant, the potential of this battery changes with the pH of the solution to be tested. However, measuring the potential generated by the battery in an acidity meter (pH meter) is difficult because its electromotive force is very small and the impedance of the circuit is very large, ranging from 1-100M Ω; Therefore, the signal must be amplified enough to drive a standard millivolt meter or milliampere meter.
3. The basic function of a reference electrode is to maintain a constant potential as a control for measuring various deviation potentials. The silver silver oxide electrode is currently a commonly used reference electrode in pH.
