8 categories and characteristics of moisture testers （ meters )

Moisture tester is also called moisture meter, moisture analyzer, fast moisture analyzer.
At present, conventional moisture testers can be divided into 8 categories:

1. The infrared/halogen moisture analyzer adopts the principle of infrared radiation source drying weight loss method, which is easy and fast to operate, with 0 consumables and accurate measurement results. It can be widely used in medicine, grain, feed, seeds, grain, tobacco, chemical industry, tea, food Rapid determination of moisture content of samples in laboratories and production processes in industries such as meat, textiles, paper, rubber, plastics, batteries, and environmental protection.
2. The Karl Fischer moisture analyzer belongs to the chemical method, the Karl Fischer coulometric method, the electric quantity method and the Karl Fischer volumetric method to measure the moisture in the sample, which overcomes the low accuracy of the Karl Fischer titration instrument, the large amount of electrolyte used, The operation is cumbersome and other disadvantages. The advanced automatic control circuit and large electrolytic current and current automatic control technology are used. The measurement results are directly displayed digitally. The appearance and structure are novel and light. The instrument is more reliable and easy to use. The electrolyte can be used repeatedly .
3. The neutron moisture meter method is also called the neutron meter method. The neutron source is inserted into the soil to be tested through the probe tube, and the fast neutrons emitted by it continuously collide with various elements in the soil and lose energy, thus slowing it down. Among them, when fast neutrons collide with hydrogen atoms, they lose the most energy and are more likely to be moderated. Therefore, the higher the water content in the soil, that is, the more hydrogen atoms, the greater the density of the slow neutron cloud.
4. 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.
5. 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 granular, The moisture determination in powdery and viscous solid samples can also be applied to the moisture determination in petroleum, kerosene and other liquid samples.
6. The near-infrared moisture meter works according to the principle that water molecules absorb particularly strong near-infrared light of certain wavelengths. Water molecules have characteristic absorption peaks in the near-infrared Han region. Water molecules strongly absorb nearby near-infrared light. If the substance to be measured is irradiated with near-infrared light of these two wavelengths, the moisture content of the substance can be measured by measuring the degree of attenuation of the transmitted or reflected light.
7. The resistance and capacitance method moisture analyzer, that is, the resistance method and the capacitance method moisture analyzer, according to the quantitative relationship between the moisture in the sample and the resistance value and capacitance value, convert the resistance value or capacitance value into a measurable quantity of electricity, through the measurement of the quantity of electricity Get the moisture value in the tested sample.
8. Oven method moisture analyzer, the oven method mostly refers to the 105 ℃ constant weight method, this method is one of the national standard methods, and the measurement results are arbitrative, but this method has a long measurement cycle and usually takes about 4 hours. The measurement results are easily affected by external factors and human factors, and have certain requirements for operators, which cannot meet the needs of rapid detection.
   Precautions for using the moisture tester:
9. When measuring, the instrument and the sample to be tested should be at the same ambient temperature, otherwise a large error will be caused.
10. For each sample, the sampling and measurement should be repeated 3 times, and the average value should be taken as the true result.
11. The instrument should be protected from shock and moisture, and kept clean and dry.
12. After using the instrument, remember to turn off the power. When the instrument is not used for a long time, the battery should be taken out to avoid corrosion of the machine parts.
13. When the adjustment cannot reach the full scale, the battery must be replaced with a new one.
14. Due to the continuous improvement of grain varieties, the electrical parameters of grain are also constantly changing. If the measurement error is too large due to the variety change, you can choose one of the six scales of the instrument’s electric meter to read the indication value of the electric meter: also It can be compared with the value measured by the constant weight method at 105°C to obtain a correction value for correction; the actual moisture value can also be directly measured.