Fundamental
pH meter, i.e. pH meter, an instrument is used to determine the pH of the solution, the electrochemical properties of the hydrogen ion concentration in solution was measured to determine the pH of the solution sensor. The negative logarithm of the hydrogen ion concentration is called pH. Typically a pH of 0 ~ 14.25 ℃ neutral water pH of 7, pH value of less than 7 is an acidic solution, pH values greater than 7 is alkaline. Temperature has a greater impact on the water ionization coefficient, causing the neutral pH value changes with temperature. The principle of pH meter pH measurement is the use of potential analysis, ion activity and establish a relationship between EMF measuring galvanic current is measured by pH. Potential measurements were used to measure pH or acidity of the most sophisticated methods.
pH meter from three components
(1) a reference electrode;
(2) a glass electrode, whose potential is dependent on the pH of the surrounding solution;
(3) a galvanometer, the galvanometer can measure small potential difference in the resistance great circuit. As a result of the latest design and solid electrode circuit technology, and now the best pH can distinguish 0.005pH units.
First, the technical performance:
1, measuring range: 0-14.0PH
2, Level: 0.1
3, LCD, portable, equipped with a composite electrode E201
4, PH measurement range: 0.001 ~ 14.00pH, measurement accuracy: ± 0.1pH
5, temperature compensation range:
6. Power supply: DC 9V battery 1
7, Dimension: 120 × 40 × 34mm
8, Weight: 110g
Second, the instrument appearance and operation of button functions and locations
1. Display: (LCD)
2, the power switch: (ON / OFF)
3, the slope of the regulator: (SLOPE)
4, the detent adjustor: (AP)
5, the electrode connecting seat: (BNC)
6, the weight in the rear of the instrument :()
Third, the use
1. Open the back cover into the battery.
2, in the BNC socket connection electrode, and turn on the power (press the switch)
3, washed with pure water and wipe dry electrodes, the electrodes are placed within PH6.86 standard solution, after agitation still place the display value is stable, then a small screwdriver to adjust the position regulator (AP) so that the display is 6.86PH (at 25 ℃). If you use two-point calibration, you can reuse the second standard solution, and then adjust the slope regulator (SLOPE).
4, the calibration is completed after cleaning the electrode with pure water and wipe dry.
5, after the electrode was placed in the test solution to be placed slightly agitated static display value is stable, that is, the PH value of the solution.
6. After the measurement, the power switch OFF (open position), and remove the electrodes, put the protective cap.