|AS-3012 is a BET Analyzer that performs surface area analysis on ISO 9277 Determination of the specific surface area of solids by gas adsorption using the BET method, the principle of the popular physical adsorption isotherms, specifically static volumetric method by full computer control without human monitoring. AS-3012 automatic surface area and pore size analyzer (nitrogen unit system), can analyze two samples and prepare two samples simultaneously, the unit operates in English Windows XP system, the instrument can perform a single point, multi-point BET surface area, BJH mesoporous, pore distribution, pore size and total pore volume and area, and the average pore size, range of specific surface area from 0.01m 2 / g to no limit, range of pore size 0.35-400nm, it can be used in many applications.|
|Test method: BET Static volumetric method of vacuum
Adsorbed gases: Nitrogen
Range of SSA: 0.01m2/g to unknown limit
Range of Pore Size: 0.35-400nm
Report: BET SSA/ Adsorption and desorption isotherms/BJH /BJHpore volume analysis/ /total pore volume/total pore area
Pressure measurement range: 0-120KPa
Pressure measurement accuracy: ±0.1% FS
Level control system: Auto coolant applied for specific temperature
Software control system: INTERNET remote control
Liquid nitrogen container: 4L
Container hold time: 48hrs
Sample tube material: glass
Sample tube vol.: 2－10mL
Vacuum pumping speed: 30L/min
Vacuum pump: 7X10-2Pa (7X10-4torr)
Size & Weight: D460 x W510 x H785 mm, 70 kg（Host）
Power: AC220V 100W
|●Combination of fully-enclosed modules with industrial automation control.
AS-3012 is designed and installed on basis of fully-enclosed modular design. It is divided into modules of control system, vacuum air path system and module of data analysis, acquisition, storage and transmit, each module contributes to the stability of unit. In case the experimental conditions are ready, operator simply sets the parameters and click Start, the following procedures are automatically done without human control or monitoring, therefore human disturbance and the error rate are minimized and the efficiency of laboratory work and accuracy of the test are maximized.
●Imported solenoid valve and sensor work with ingenious control systems.
Programmable control system and imported solenoid valve from Japan contribute to low heat, excellent anti-interference ability, high stability and long working life. Sensor of stepping control system for liquid nitrogen ensures the constant position of liquid level to sample tube, as a result eliminates measurement error due to introduction of dead volume change. High-precision pressure sensor improves the accuracy to the 0.15% of the readings, much better than the 0.15% accuracy full scale (FS) sensors. Unique system for gas inlet and control effectively prevents the splash during sample vacuum and air intake. It also prevents the pipeline from dirty, the matter of the sample from loss and data from deviation due to dramatic pressure change. Integrated cartridge pipeline reduces leakage, dead air space and improve the ultimate vacuum. Special gas closed-system made of stainless steel ensures he tightness of the pipeline and prevents the sample from contamination.
●Powerful software is developed by renowned professionals.
USB connection between the computer and the unit makes for fast communication. Adoption of multiple theoretical models in the analysis gives users a complete analysis on materials. Automatically saved test data contributes to easy management and query. Result analysis report is automatically printed out after test. In case of power failure, t est can be continued after re-power to save test time.
●Superior design, precise mechanical processing and high quality accessories.
Outer case is designed in line with the modern requirement and corrosion is prevented by high quality plastic coating. Robust mechanical parts give the unit a stronger bone and hence a longer working life. Selected valves and tubes make for stability and reliability of the unit. Vacuum pump is imported from USA , it gives the users a higher vacuum limit, effective oil return prevention as well as a smooth and safe operation.
-Adsorbent (zeolite, molecular sieve, activated carbon, silica gel, activated alumina, etc.);
-Catalyst (platinum, palladium and other metal catalysts, etc.);
-Ceramic materials (alumina, zirconia, silicon nitride, silicon carbide, quartz, etc.);
-Battery materials (lithium manganese oxide, graphite, polymer battery materials, alkaline materials, etc.);
-Magnetic powder materials (iron oxide, ferrite, etc.);
-Nano-powder materials (ceramic materials, metal materials, silver, iron, copper, tungsten powder, nickel powder and metal powder);
-Environmental Sciences (sediment, suspended solids, etc.);
-Others (such as ultra-fine fibers, porous fabric, polymer composites, etc.).
|The method specified involves the determination of the amount of adsorbate or adsorptive gas required to cover the external and the accessible internal pore surfaces of a solid with a complete monolayer of adsorbate. This monolayer capacity can be calculated fro the adsorption isotherm using the BET equation. Any gas may be used, provided it is physically adsorbed by weak bonds at the surface of the solid (van der Walls forces), and can be desorbed by a decrease in pressure at the same temperature.
Nitrogen at its boiling point (about 77 K) is usually the most suitable adsorptive. If the sensitivity of the instrument when using nitrogen is insufficient for low surface areas, adsorptives of heavier molecules or of vapour pressure lower than nitrogent, e.g. krypton, may be used. The results of measurements with different adsorptives may deviate from each other because of different molecular areas, different accessibilities to pores and different measuring temperatures.
The adsorptive gas is admitted to the sample container which is held at a constant temperature. The amounts adsorbed are measured in equilibrium with the adsorptive gas pressure p and plotted against relative pressure, p/p0, to give an adsorption isotherm. Adsorption isotherms may be obtained by volumetric, gravimetric, calorimetric or spectroscopic measurement or by the carrier gas method using continuous or discontinuous operation.
In order to determine the adsorption isotherm volumetrically by the discontinuous method, known amounts of adsorptive are admitted stepwise into the sample container. At each step, adsorption of the gas by the sample occurs and the pressure in the confied volume falls until the adsorbate and the adsorptive are in equilibrium. The adsorbed volume may be conpensated by the introduction of calibrated increments of gas so that the pressure remains constant. The amount of gas adsorbed is the difference between the amount of gas adsorbed is the difference between the amount of gas admitted and the amount of gas filling the dead volume (free space in the sample container, including connections), which is determined by application of the general gas equation. The various volumes of the apparatus and their temperatures should be taken into account.
The dead volume must be determined before or after the measurement of the adsorption isotherm. The calibration is done volumetrically using helium at the measuring temperature. It should be noted that some materials may absorb helium. In this case, corrections can be made after measuring the helium isotherms. During sample measurement and determination of the dead volume, it is recommended that the liquide level in the collinig bath be maintained, unless otherwise compensated, at least 50 mm above the sample and constandt to within 1 mm. The determination of the dead volume may be avoided using difference measurements, i.e. by means of reference and sample tubes connected by a differential transducer.
In the continuous volumetric measurement, the amount of admitted adsorptive may be calculated from the pressure difference and the duration of the gas flow through a calibrated capillary or metering valve.
|What is adsorbent in BET surface analysis?|
|adsorbent is a solid which adsorbs the measuring gas.|
|What is adsorbent in BET analysis?|
|-adsorbent is a solid which adsorbs the measuring gas.|
|What is adsorptive in surface area analysis?|
|-adsorptive represents the measuring gas to be adsorbed|
|What is physisorption for a BET analyzer?
-physisorption is weak bonding of the adsorbate, reversible by small changes in pressure and temperature.
|What is adsorption in surface analysis?
-adsorption is enrichment of the adsorptive at the external and accessible internal surfaces of a solid.