What are the main test methods for moisture determination
The classical moisture analysis method has been gradually replaced by various moisture analysis methods, and the main moisture analyzers currently on the market are
There are mainly halogen moisture meters, infrared moisture meters, dew point moisture meters, microwave moisture meters, Coulomb moisture meters, Karl Fischer moisture analyzers, and some special moisture meters. The determination methods of these instruments are easy to operate, high in sensitivity and good in reproducibility, and can measure continuously and display data automatically.
1. The infrared moisture meter is easy to operate, less time-consuming, and the measurement result is accurate. Therefore, the infrared moisture meter can be widely used in the experimental analysis and daily purchase control and process detection of chemical, pharmaceutical, food, tobacco, grain and other industries.
2. The Karl Fischer method is a classic method, also known as a trace moisture analyzer, which is mainly used in the detection of samples with low moisture content. After improvements in recent years, the accuracy has been greatly improved and the measurement range has been expanded. Listed as a standard method for the determination of moisture in many substances.
3. The dew point moisture meter is easy to operate, the instrument is not complicated, and the measured results are generally satisfactory. It is often used for the determination of trace moisture in permanent gases. However, this method has a lot of interference, and some easy-to-cool gases, especially when the concentration is high, will condense before water vapor and cause interference.
4. The microwave moisture analyzer uses the microwave field to dry the sample, which accelerates the drying process. It has the characteristics of short measurement time, convenient operation, high accuracy, and wide application range. It is suitable for particles of grain, paper, wood, textiles, and chemical products. It can be used for the determination of moisture in solid, powdery and viscous solid samples, and can also be used for the determination of moisture in petroleum, kerosene and other liquid samples.
5. Coulomb moisture meter is often used to measure the moisture contained in the gas. This method is easy to operate and responds quickly, and is especially suitable for the determination of trace moisture in gas. If it is determined by general chemical methods, it is very difficult. However, the electrolysis method is not suitable for the determination of alkaline substances or conjugated dienes.
