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An industrial conductivity meter is a type of component analyzer that is widely used. It determines the concentration of the solution indirectly by measuring its electrical conductivity. It can be used to analyze ordinary electrolyte solutions, such as the concentrations of acids, bases, salts, etc., as well as gas concentrations. When analyzing gas concentrations, the gas is dissolved in a solution or absorbed by a conductive fluid; the concentration of the gas being analyzed is then determined indirectly by measuring the conductivity of the solution or conductive fluid. When analyzing the concentration of acid and alkali solutions, it is commonly referred to as a concentrator. It is commonly referred to as a salinometer or salt meter when used to measure the salt concentration in the water supply and steam (in the condenser) of positive pressure drive systems. A conductivity meter mainly consists of a cell, a measurement circuit, an indicator, etc.; high-precision conductivity meters also have temperature and capacitance compensation circuits. http://yunrun.com.cn/upload/201604/08/201604081032028821.jpg Mettler-Toledo conductivity meter; Maintenance of conductivity meters: 1. Check whether the flow rate of the solution being measured by the detector is normal, whether the temperature meets the requirements of the instrument, and examine whether there are any leaks in the various pipelines. 2. Check whether the instrument readings match those of the associated recorder; if the recorder runs out of ink or has paper feed issues, address them promptly. 3. Check the instrument readings and recording data to determine whether they are normal when compared with the process parameters or manually analyzed values. 4. Inspect the insulation and steam tracing during winter. 5. Any fault that cannot be resolved should be reported promptly; when it endangers the safe operation of the instruments, measures such as emergency shutdown of the instruments should be taken, and the process engineers should be informed. 6. Are there any cracks, gaps, signs of wear or deterioration inside the cell? Is the platinum black coating on the electrode surface intact? Are there any signs of corrosion or discoloration on the electrodes? Is the protective layer surrounding the electrodes in good condition? Are there any signs of changes in the electrode position due to excessive liquid flow velocity? Is the leakage resistance of a dry cell greater than 50 MΩ? Is the drain port blocked? 7. Regularly inspect and maintain the pretreatment system and its components, detectors, converters, recorders, and alarms. 8. When cleaning the detector, remove the electrodes from the housing, and submerge both the electrodes and the housing in a hydrochloric acid solution with a concentration of 1%-2% (make sure that the wiring terminals of the electrodes are not submerged). Use a brush to clean the inside of the electrodes and the housing. After cleaning, rinse them multiple times with distilled water or deionized water until the water is neutral, then reinstall the electrodes into the housing and secure them in place. Common faults of conductimeters and their solutions. Fault symptoms, causes of conductimeter faults, and methods for dealing with them: The instrument reads zero – The power supply is not connected; check the power supply circuit. The electrode circuit is broken – Check the connections in the electrode circuit. The instrument reads at its maximum value – There is a short circuit in the connections of the detector electrodes; check those connections. The conductivity of the solution exceeds the instrument’s maximum scale value – Measure the solution’s conductivity using a laboratory conductimeter, or empty the solution from the cell. The instrument reads too high – The terminals of the detector are damp; use a bulb to remove the liquid between the terminals, then dry them with filter paper. http://yunrun.com.cn/upload/201604/08/201604081032241594.jpg Conductimeter electrodes (conductivity sensors) – What does a conductivity sensor measure? A conductivity sensor measures the electrical conductivity of a solution. Ions in a solution give it electrical conductivity: the higher the ion concentration, the higher the conductivity. How do you calibrate a conductivity sensor? A conductivity sensor can be calibrated in a solution with a known conductivity (just as a pH sensor is calibrated in a solution with a known pH). Alternatively, you can also use a device containing a series of highly precise resistors to replicate known conductivity measurements. How many types of conductivity sensors are there? There are two types of conductivity sensors: contact-type and inductive-type. When using a contact sensor, the electrode for measuring conductivity is in direct contact with the solution. An alternating voltage is used for the electrodes. This can cause ions between the electrodes in the solution to move back and forth, thereby generating a current; measuring this current converts it into a conductivity value. Such sensors are highly suitable for measuring low-conductivity solutions with very low levels of solid particles, as these particles can accumulate around the electrodes and interfere with measurements of pure water and similar substances. For solutions with high electrical conductivity, or if the solution is likely to corrode the electrodes or contain a large amount of solid particles, inductive sensors are required. These sensors use two coils enclosed in plastic. A current flowing through one coil induces an induced current in another coil. The amount of induced current generated depends on the conductivity of the solution. In what device is conductivity measured? Conductivity is measured in siemens/cm (S/cm). A conductivity of 1 S/cm is quite high; therefore, the vast majority of conductivity measurements are conducted in mS/cm (one thousandth of S/cm) or μS/cm (one millionth of S/cm). Drinking water typically ranges from 50 to 1500 μS/cm. Source: Changhui Automation http://yunrun.com.cn/