Specific surface area tester

Jingwei Gaobo focuses on the research and sales of specific surface area testers and is a well-known brand both domestically and internationally. And in2014Obtaining the certificate of "Domestic Good Instrument" for the specific surface area tester in the year, customer recognition is the driving force behind our manufacturing and research and development of the specific surface area tester!

JW-BK400Four channel fully automaticBETSpecific surface area tester, the first high-precision instrument in China to truly achieve independent operation of four stations in parallelBETCompared to surface professional measuring instruments, it has faster testing speed, higher efficiency, and extremely high cost-effectiveness, making it very suitable for powder materialsBETFaster detection than surface inspection.

Performance parameters of specific surface area tester:

Instrument model:JW-BK400Specific surface area tester

Principle and method: Gas adsorption method, static capacity method;

Testing function: Single point, multi-pointBETSpecific surface area;LangmuirSpecific surface area;t-plotMeasurement of surface area using the method; Single point adsorption total pore volume measurement;

Test gas: Nitrogen, oxygen, hydrogen, argon, krypton, carbon dioxide, methane, etc;

Test scope: specific surface0.005m2/gUp to no limit;

Repetition accuracy: Specific surface area≤± 1.5%；

Testing efficiency: Average specific surface area per sample10min；

Analysis Station: 4A completely independent sample analysis station, capable of simultaneous degassing;

Lifting system: 4A sample analysis station is set up in situ4Set up an independent lifting system, electrically controlled and automatically controlled, and do not interfere with each other;

Vacuum system: All stainless steel multi-path parallel vacuum pumping pipeline system, vacuum pumping speed fine adjustment valve system * * technology, can be used in2-200ml/sAutomatic adjustment within the range;

Vacuum pump: Mechanical vacuum pump, ultimate vacuum10^-2Pa；

Degassing system: Modular design of vacuum degassing pretreatment system for co location and cross location. standard configuration4Install a same position degassing system,4An independent heating package,4A set of independent temperature controllers, both capable of programmable temperature control, with up to several heating steps10Step; Optional external ectopic placement4Vacuum degassing system;

Degassing temperature: room temperature—400℃, accuracy±1℃；

Pressure sensing: Imported pressure sensor4Support, accuracy≤± 0.15％；

Voltage division range:P/P0 10-4-0.99；

Pressure control: Balanced pressure intelligent control method, pressure controllable interval<0.1KPa, adsorption High pressure points can be automatically controlled;

Data collection: Ethernet data collection, fast collection speed, high accuracy, compatibleWindows 7/XP 32/64Positional system;

Product features of specific surface area tester:

●Completely independent four station parallel analysis, capable of simultaneous degassing and simultaneous analysis of four samplesBETCompared to surface and degassing treatment, the testing efficiency is extremely high;
●External4Degassing station, dedicated mechanical vacuum pump, High degassing temperature400℃；
●Multiple points of four samplesBETCompared to surface testing,30It can be automatically completed within minutes;
●Adopting a liquid nitrogen surface control comprehensive system and software compensation technology to ensure a relatively constant non-uniform temperature field in the sample chamber throughout the entire testing process, in order to ensure the accuracy of analysis, suitable for various cold baths such as liquid nitrogen, liquid argon, ice water, etc;
●Equipped with a large capacity vacuum glass inner Dewar flask and anti liquid nitrogen evaporation unit to ensure the sustainability of the experiment72Hour;
●Self controlled adjustable multi-channel parallel vacuum pumping system, built-in anti splash unit, and“STEP CUT”Anti splash program, effectively preventing ultrafine powder from flying and completely avoiding instrument contamination;
●The instrument control panel is equipped with valve position control indicator lights, allowing experimenters to more intuitively and clearly see the working status of the control valve, with a user-friendly design;
●Intelligent control technology for equilibrium pressure, automatic judgment and data collection of sample adsorption equilibrium pressure;
●Ethernet data acquisition and processing software, guided operation, one set of software can control multiple instruments simultaneously, and can be remotely controlled;
●The instrument can be upgraded for aperture analysis;

Application areas of specific surface area tester:

●Rubber materials: carbon black, white carbon black, calcium carbonate, zinc oxide, silicone Chemical raw materials such as silicon oxide;
●Battery materials: lithium cobalt oxide, lithium manganese oxide, lithium iron phosphate, graphite, ternary materials Positive and negative electrode materials such as separators;
●Materials for desulfurization and denitrification: denitrification catalysts, etc;
●Food additives: starch, activated clay, bentonite, etc;
●Magnetic materials: iron oxide, ferrite, manganese oxide, etc;
●Nanomaterials: Nanoceramic powders (alumina, zirconia, yttrium oxide, silicon nitride, etc.) Silicon carbide, nano metal powders (silver powder, iron powder, copper powder, tungsten powder, nickel powder, etc.) Nano polymer materials, carbon nanotubes, etc;
●Coal mining industry: coal, ore, rock, shale gas, coalbed methane, etc;
●Other materials: ultrafine fibers, porous fabrics, composite materials, soil, etc.

Technical Tips:
Introduction to Practical Techniques for Specific Surface Area Analysis:

There are several factors that have a significant impact on the testing process and results of gas adsorption method, such as surface area and pore size distribution (porosity). Effective analysis of test results requires consideration of these factors. These factors include: sample processing conditions, characteristics of adsorbate gases, different testing methods, etc., which will be described in detail below.

Sample processing conditions

Due to the close relationship between the determination of specific surface area and porosity and the outer surface of particles, and the key to adsorption method determination is the adsorbate gas molecules“effectively”Adsorbed on the surface of the tested particles or filled in the pores, therefore, whether the surface of the sample particles is“clean”crucial. The main purpose of sample processing is to release the surface occupied by non adsorbate molecules as much as possible, in order to facilitate the surface adsorption of adsorbate molecules during the testing process. Generally, pre-treatment is required before sample determination, and the treatment method is selected according to the characteristics of the measured sample. In general, most samples need to remove the water molecules adsorbed on their surface, so it is higher than100℃ (usually taken as105℃-120Drying at normal pressure (℃) can achieve this goal, which is beneficial for simplifying the operation process. For samples containing micropores or with strong adsorption characteristics, impurity molecules are easily adsorbed at room temperature and pressure, or many other molecules are adsorbed on the surface during the manufacturing process. It is usually necessary to perform degassing treatment under vacuum conditions, and sometimes an inert protective atmosphere must be introduced during the pretreatment process to facilitate the desorption of impurities on the sample surface. In summary, the purpose of sample pretreatment is to make the surface of the sample clean, in order to ensure accurate and effective measurement results of specific surface area and pore size (porosity).

Characteristics of adsorbate gas

In the analysis and testing of surface area and pore size distribution of gas adsorption method, the adsorption of adsorbate gas The basic requirement is that its chemical properties are stable, and the adsorption process will not have any impact on the performance and surface adsorption characteristics of the sample itself, and it must be reversible physical adsorption. Nitrogen is The commonly used adsorbate, practice has shown that nitrogen is chosen as the adsorbate for the determination of the vast majority of substances, and the accuracy and repeatability of the test results are ideal. For samples containing micropores, if the micropore size is very small, close to the diameter of nitrogen molecules, on the one hand, nitrogen molecules are difficult or impossible to enter the micropores, resulting in incomplete adsorption; On the other hand, the adsorption characteristics of gas molecules in pores with diameters equivalent to their own are very complex and are influenced by many additional factors, so the adsorption capacity cannot fully reflect the size of the sample surface area. For such samples, argon or krypton with smaller molecular diameters are generally used as adsorbents to facilitate sample adsorption and ensure the validity of test results.

Testing method factors

Different testing methods also have a significant impact on the test results, and each testing method has its own advantages and disadvantages. In the continuous flow method, due to the use of“contrast”The principle of the method can effectively reduce the impact of sample processing on test results compared to the capacity method. By comparing, to some extent, the errors caused by imperfect processing between the standard sample and the tested sample can be offset, provided that the surface structure and adsorption characteristics of the two samples are similar and the processing conditions are the same. This is very valuable for testing used for on-site product quality control purposes, reducing sample processing time and greatly improving testing efficiency. If the same substance is used as the standard sample and the tested sample, due to the similar surface structure and adsorption characteristics, the specific surface area test result will be insensitive to the sample processing conditions, in other words, the error will be offset. Therefore, the continuous flow method is very suitable for on-site inspection of product quality. On the contrary, the capacity method can be said to be very sensitive to sample processing because it uses The principle of measuring adsorption capacity is that any unclean surface or other factors that affect the adsorption process of adsorbates will directly affect the measured product.