Features and working principle of acid-base concentration meter
The characteristics and working principle of the acid-base concentration meter
The acid-base concentration meter is a water quality online monitor with a microprocessor. The instrument is widely used in thermal power, chemical industry, steel pickling and other industries, such as the regeneration of ion exchange resins in power plants, chemical industry processes, etc., to continuously detect and control the concentration of chemical acids or alkalis in aqueous solutions.
Features:
1. The non-contact detection method eliminates the corrosion, pollution and polarization effects of strong corrosive media on electrodes
2. It adopts all-plastic sealed shell, which can be used for a long time in humid, dusty and corrosive environments and other harsh environments
3. The frequency conversion excitation power supply and resonance circuit and its unique signal sampling method are used to replace the single frequency excitation method, which increases the output voltage of the detection transformer hundreds of times. The flow-through sensor adopts a low-temperature magnetic structure and ferromagnetic shielding, and has no zero-point drift phenomenon, which greatly improves the accuracy, sensitivity and stability of the instrument
4. Use the microcontroller (MCU) and interface integrated circuit to conduct full digital sampling, calculation and display of the output voltage of the detection transformer and the output current of the temperature sensor, which can realize high-precision temperature compensation and local display and remote control of concentration values. transmit out
The working principle of the acid-base concentration meter:
The principle of automatic temperature compensation: the concentration of the measured solution is non-linearly proportional to its conductivity, and the conductivity of the solution changes due to the temperature, and temperature compensation is required. The temperature characteristics of various solutions are different, and it is carried out by a microprocessor. The relevant processing becomes fast and accurate, realizing the function of automatic temperature compensation.
Measuring principle: The meter uses a conductivity electrode sensor for measurement (the concentration electrode material is platinum), in order to avoid electrode polarization, the meter generates a high-stability sine wave signal and adds it to the electrode, the current flowing through the electrode is related to the concentration of the measured solution In direct proportion, the current flowing through the electrode is measured by the preamplifier and converted into a voltage signal, and the voltage signal reflecting the concentration value is obtained after program-controlled amplification, phase-sensitive detection and filtering; the microprocessor switches the temperature signal and the concentration signal Alternate sampling, after operation and temperature compensation operation, converted and displayed as the measured concentration value and real-time temperature value at 25°C.
