What is the working principle of conductivity and testing machine?
Publish Time: 2025-06-03
In modern industrial testing and environmental monitoring, conductivity and testing machine plays an indispensable role. Although its measurement target seems simple - that is, to determine the ion concentration by measuring the conductivity of the solution, to achieve high-precision, stable and reliable measurement, a series of complex electronic engineering design and signal processing technologies are involved.First of all, from the hardware structure point of view, the core components of conductivity and testing machine include sensors (probes), signal generation and acquisition modules, temperature compensation units, and data processing and display interfaces. Among them, the sensor is the part that directly contacts the sample to be measured, and its design has a profound impact on the overall performance. The current mainstream equipment adopts a four-electrode structure, which can effectively avoid the errors caused by polarization effect and contact resistance compared with the traditional two-electrode solution, thereby improving the measurement stability. This design optimization not only improves the adaptability of the instrument in different media, but also greatly reduces the calibration frequency during long-term use.Secondly, in terms of signal processing, modern conductivity and testing machines generally use AC excitation instead of DC power supply. The purpose of this practice is to prevent the occurrence of electrolytic reactions, especially in long-term measurements or high-salinity liquids. By applying an alternating current signal of a specific frequency, not only can the chemical reaction on the electrode surface be reduced, but also the anti-interference ability of the system can be improved. At the same time, in order to ensure the accuracy of the measurement signal, a phase-locked amplifier circuit is usually integrated inside the test machine to extract weak effective signals and filter out noise interference. The application of this technical means enables the equipment to maintain good measurement consistency even in a complex electromagnetic environment.Temperature compensation is an important part of conductivity testing. Since the conductivity of the solution changes significantly with temperature, it is necessary to introduce high-precision temperature sensing elements and combine them with software algorithms for dynamic correction. Currently, most high-end conductivity and testing machines use PT1000 platinum resistors or NTC thermistors as temperature detectors, combined with built-in temperature-conductivity conversion models to achieve real-time automatic compensation. Some intelligent devices even support user-defined temperature coefficients to meet the measurement needs of special samples.At the system integration level, more and more conductivity and testing machines are beginning to develop in the direction of digitalization and networking. For example, some industrial-grade equipment has RS485 or Modbus communication interfaces, which can be connected to PLC systems or DCS control systems to achieve remote monitoring and centralized data management. In addition, with the development of Internet of Things technology, some portable devices have also begun to support Bluetooth connection and APP control, which is convenient for users to quickly obtain data and analyze it on site. This trend not only improves the convenience of operation, but also provides strong support for subsequent data traceability and quality control.It is worth noting that the design of conductivity and testing machine will also focus on different application scenarios. For example, the online conductivity meter used in the water treatment plant needs to have strong corrosion resistance and explosion-proof performance; while in the laboratory environment, it pays more attention to measurement accuracy and repeatability. To this end, manufacturers will adjust key parameters such as material selection, sealing level and protection level according to the needs of the target market during the product development stage to meet the diverse usage scenarios.In summary, although the conductivity test itself is a basic physical quantity measurement process, to build a high-performance and high-stability test equipment, it is inseparable from precise electronic design, advanced signal processing technology and reasonable system architecture. It is these technical details hidden under the appearance that determine the actual performance and service life of the conductivity and testing machine, and also reflect the important value of modern testing instruments in industrial automation and scientific research.
