How many moisture determination methods do you know?
Karl Fischer Moisture Analyzer
The Karl Fischer method, referred to as the Fischer method, is a capacity-splitting method for the determination of moisture proposed by Karl Fischer in 1935. The Fischer method is the most specific and accurate method for water among various chemical methods for determining the moisture content of substances. Although it is a classic method, it has been improved in recent years to improve accuracy and expand the measurement range. It has been listed as a standard method for moisture determination in many substances.
Infrared moisture meter
Infrared heating mechanism: When far-infrared rays radiate to an object, absorption, reflection and transmission can occur. However, not all molecules can absorb far-infrared rays, only those polar molecules that show electricity can work. Water, organic substances, and high molecular substances have a strong ability to absorb far infrared rays. When these substances absorb far-infrared radiation energy and make their molecular and atomic vibration and rotation frequency consistent with the frequency of far-infrared radiation, it is very easy for molecules and atoms to resonate or rotate, resulting in greatly increased motion, which is converted into The heat can raise the internal temperature, so that the material can be softened or dried quickly.
Dew point moisture meter
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.
microwave moisture meter
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 grain, paper, wood, textiles, and chemical products. The moisture determination in powdery and viscous solid samples can also be applied to the determination of moisture in petroleum, kerosene and other liquid samples.
Coulomb moisture meter
Coulometric moisture analyzers are commonly used to measure the moisture contained in gases. 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.
