The reason why measuring pH value in pure water is special is that its ion content is extremely low and its conductivity is very small. This will result in slow response and unstable readings. Due to the lack of conductive medium, the potential signal generated by ordinary pH meters is weak and stable for a long time, and the reading is prone to drift. At the same time, it is susceptible to external interference, and pure water acts like a sponge, easily absorbing carbon dioxide from the air and generating carbonic acid, resulting in distorted pH measurement. Therefore, ordinary pH sensors are difficult to obtain accurate results in pure water, which requires the use of specially designed pure water pH meters and sensors that address these challenges through special technologies such as optimized liquid network design and reference systems to ensure accurate and stable measurements. Dalk's pH/ORP3320 instrument is specifically designed for online detection of pure water.

Main application scenarios

Pure water pH meters play a key role in multiple fields with strict water quality requirements. The following are some of the main application scenarios:

Key Technologies and Selection Points

Choosing a suitable pure water pH meter and using it correctly requires attention to the following points:

Core Technologies and Sensors:The pure water pH meter adopts multiple targeted technologies. For example, using low impedance sensitive glass film to accelerate response; The reference system of free flowing liquid complex or special gel electrolyte is adopted to maintain stable liquid connection potential; And it integrates high-precision automatic temperature compensation (ATC) function to correct errors caused by temperature changes.

Equipment selection guide:

Online vs laboratory: Industrial processes (such as power plants and chip factories) that require 24-hour continuous monitoring should use online analyzers; For quality inspection or scientific analysis, a laboratory desktop pH meter is more suitable.

Pay attention to sensor specifications: It is necessary to confirm whether the sensor is clearly labeled as suitable for "pure water" or "low conductivity water". For example, METTLER TOLEDO's pHure Sensor series, Sanxin MP512-02's 2503D-C pure water pH composite electrode, and Dalk's 110/130 electrode are all designed specifically for pure water.

Examine key performance indicators:Check the accuracy, response time, stability and other parameters of the product. For example, some models have an accuracy of ± 0.002pH and are equipped with a dedicated pure water pH measurement mode.

Usage and maintenance tips:

Careful installation and calibration: Install strictly according to specifications and calibrate using a standard buffer solution that is similar to the pH of the pure water being tested.

Avoiding pollution is the core: all utensils that come into contact with the sample must be clean and exposed to air for as short a time as possible.

Careful maintenance of sensors: Regularly clean and maintain the electrodes according to the instructions. For example, Rika Sensor suggests that its pH sensor should be soaked in 3 mol/L KCl protective solution when it is stopped, rather than stored in distilled or deionized water.

In general, pure water pH meters are water quality "monitoring devices" in higher fields such as electricity, microelectronics, pharmaceuticals, and scientific research. Understanding its working principle, selecting appropriate equipment according to specific application scenarios, and standardizing operation are necessary to effectively ensure the stable operation of pure water systems and the high quality of products.