The type, principle and selection of moisture analyzer

At present, there are many different kinds of moisture analyzers on the market. When many customers choose moisture meters, it is unclear which principle moisture analyzer is more suitable for their own use. As the computer network has accelerated the communication and release of information, it has also caused the real producers and distributors in the market to get confused. Many distributors have not published the formal technology and after-sales training of the manufacturers, and have published directly on the site themselves. Therefore, it is difficult for end users to select a moisture meter that is suitable for their own. After the end user receives the moisture meter, it will find the goods are not on the board and some counterfeit OEM products; at the same time, most dealers put the manufacturer's after-sales service on the phone. Change to your own company phone, which will result in end-user technical support and after-sales service will not be timely and effective. Most customers encounter problems that are easy to solve because they are reluctant to tell the end user to the manufacturer and the end user cannot find the manufacturer. This causes the end user to create a big misunderstanding for the manufacturer. First of all, the test of the product is inaccurate and the stability is poor; followed by the manufacturer's after-sales service is not good, not timely, not in place, poor attitude and so on. Therefore, it is recommended that when customers purchase products, try to directly select the manufacturer's cooperation and facilitate the timely service. The following is a brief introduction to the principle and use of various moisture meters, so that everyone can choose the moisture meter that best suits their needs.

The moisture meter can be roughly divided into:

1, halogen moisture analyzer,

2, infrared moisture meter,

3, far infrared moisture meter,

4, near infrared moisture analyzer,

5, Karl Fischer moisture analyzer,

6, capacitance moisture meter,

7, resistance moisture meter,

Brief description:

1, resistance moisture meter: It is based on the size of the resistance, to determine the size of moisture. This type of product has a rectangular shape. In general, the instrument has a long probe and some probes.

Features: Easy to carry and cheap. There are a few tens of dollars, but also a few hundred dollars, but the highest but 2,000 yuan.

The use of the environment: generally used in the field, or a large number of incoming inspection (such as several tons or dozens of tons)

Use of the industry: food acquisition, timber acquisition, chemical, paper batch incoming inspection.

Disadvantages: no accuracy, large error, only moisture measurement range, such as 3%-25%. Can only be used as an aid.

2. Capacitance Moisture Meter: The principle of this type of moisture meter is generally similar to a tea cup. The sample is poured in and the result will be soon.

Features: Cheap and fast. More than a thousand, the highest but 2,500 yuan.

The use of the environment: the wild, but also many small businesses for laboratory testing.

Use of the industry: grain purchases, tea purchases, etc.

Disadvantages: no accuracy, large error, only approximate moisture measurement range, and a lot of standard samples are required for different samples before testing. There are also strict requirements for the accumulation state of the product, so there is no true degree of accuracy. There are more grain households in the Central Plains and a small number of users in the Northeast.

Note: The above two types of moisture meters are currently mainly used for acquisitions in the market, but now many growers know that this moisture meter is inaccurate, so the product is facing a severe test.

3, Karl Fischer moisture analyzer history in 1935, as long as it is used in the chemical industry, testing the moisture with volatile substances. The early period is mainly measured by capacity analysis. Domestic production of cheaper two or three thousand dollars, but the quality of the manufacturers are mainly Shandong Zibo sub-instrument, the price range. It is more expensive abroad.

Karl Fischer can be divided into:

(1) Volumetric method: It is divided into visual inspection method and electric quantity method (2), Coulomb method: The effect of this method with large moisture content is not very good.

Use industry: Karl Fischer moisture meter is suitable for moisture testing in volatile substances, such as: toluene, xylene, paint and other industries.

Note: The moisture meter of this method needs consumables, and the consumables are chemical reagents, which are harmful to the human body. Therefore, the enterprises that purchase this product generally have to provide certain protective measures for specific operators. In order to avoid serious consequences.

4. Near-infrared moisture analyzer: The moisture analyzer is an on-line moisture testing instrument. It is mainly used in the production line to monitor moisture in real time. The near-infrared moisture analyzer has a relatively high requirement for the uniformity of the sample, and a database must be established before installation. If the sample is replaced during the test, the data must also be replaced. Frequently, this product should be calibrated with an infrared moisture analyzer. In other words, when buying an online moisture analyzer, you should also buy a standard infrared moisture analyzer and often calibrate the online moisture analyzer. At present, there are less domestic production, mainly import, but the price is very expensive, hundreds of thousands, this price is not affordable for the average company.

On-line moisture analyzer technology matured earlier in foreign countries, especially in agriculture, because foreign agricultural products are mostly one species, and more species can appear in the same region in China, so testing is difficult. Representatives of the United Kingdom and Germany.

Principle: Based on the principle that near-infrared wavelengths are absorbed by water molecules, the change in near-infrared energy at a specific wavelength is analyzed.

Use industry: tobacco, ore, agriculture and so on.

5. Far-infrared moisture analyzer: It is generally used for laboratory product testing, but this type of product has a long test time and slow heating. It is not suitable for some products with strict requirements and high moisture content, such as seeds, vinasse, etc. Long-term value has a great influence.

6. Infrared moisture analyzer: The biggest difference between infrared and far infrared and near infrared is its wavelength is not the same.

Infrared rays have a strong penetrating power, because the heated and dried substance absorbs far-infrared radiation energy at a certain depth inside and surface molecules and generates a self-heating effect, so that the solvent or water molecules evaporate and the heat is even, thereby avoiding the thermal expansion. Deformation and qualitative change caused by different degrees, so that the appearance of the material, physical and mechanical properties, fastness and color, etc. remain intact.

Currently the most representative manufacturer in the market: Shenzhen Guanya Electronic Technology Co., Ltd.

7, halogen fast moisture analyzer: Halogen moisture meter is a new breed in recent years, once listed on the market by many companies. The heating source adopts a ring halogen tube, the heating is relatively uniform, and the performance is stable. But the price is slightly more expensive than infrared.

Features: Circular heating, stable performance, short test time Use industry: Except flammable, explosive, volatile industry Use environment: laboratory, production lines, etc. Based on the above and the characteristics of halogen moisture meter high cost performance, it also created a lot of domestic distribution Commercial counterfeit labeling and three- and four-line manufacturers have widely advertised on the Internet and sold counterfeit halogen moisture meters for sale. When the customer bought it back, he discovered that it was not even possible for the board to distinguish whether it was a halogen moisture meter. The markets in Guangdong and Shanghai are particularly confusing. Many dealers are also selling hot-wire heating products to customers. They say that they are halogen moisture meters. Customers therefore pay a price several times more. Because they are counterfeit, they can't reach the original level. Halogen technical indicators, dealers generally do not dare to do phone tracking service and technical support work. It is recommended that when customers buy products, they must be sure about the performance of the product, the brand, the manufacturer, and whether there is a production license for measuring instruments issued by the quality and technical supervision department. When the purchase contract is signed, the above content will be written into a written form to facilitate later resolution of the dispute.

In addition, three-wire, four-wire manufacturers are using balanced magnetic sensors, advantages of cheap, disadvantages: easy aging, instability. Customers can buy two or three thousand for this option.

8, the current domestic production of high-end moisture meter manufacturers are as follows for your reference:

(1) Shenzhen Guanya Electronic Technology Co., Ltd. (2) and Shanghai Precision Scientific Instruments are:

(1): METTLER (2): Sartorius