PS Series Pore Size and Surface Analyzer

 Selection Guide

Test principle:

Under the condition of low temperature (such as liquid nitrogen bath, 77.3k), a certain amount of adsorbate gas (such as N2) is introduced into the sample tube, and the adsorption partial pressure is directly measured by controlling the equilibrium pressure in the sample tube, and the adsorption amount of the partial pressure point is obtained by the gas state equation (PV = NRT); The adsorption isotherm can be obtained by increasing the adsorption equilibrium pressure by gradually putting in the adsorbate gas; the desorption isotherm can be obtained by gradually drawing out the adsorbate gas to reduce the adsorption equilibrium pressure; the relative dynamic method does not require carrier gas (he) and the liquid nitrogen cup to rise and fall repeatedly; because the sample to be tested is In a fixed volume sample tube, the adsorbate does not flow relative to the dynamic chromatography, so it is called the static capacity method;

Adsorption and desorption isotherm；    

BET specific surface measurement (single point/multi-point method)

Langmuir Specific surface;

BJH method pore volume and pore size distribution;

MK-plate method (parallel-plate model) pore volume and pore size distribution;

D-R method micro-hole analysis;

T-plot method (boder) micro-pore analysis;

H-K method (Original) micro pore analysis;

Degassing pretreatment system: number of degassing stations: 2, 4, 8 optional;

Full automatic degassing: it does not adopt the manual control of the split type, but adopts the full-automatic program control integrated with the main engine. It starts and stops at a fixed time, the vacuum pump starts and stops automatically, and the program heats up and ends at a fixed time to realize the unattended test and the degassing treatment of samples;

Independence: the test system and degassing system are independent of each other, and the test process and degassing treatment of samples can be carried out at the same time;

Two groups of independent temperature control: two groups of different degassing temperature, different degassing time can be set;

Degassing mode: it has two optional functions: "ordinary heating vacuum molecular diffusion mode" and "molecular displacement mode";

Degassng LCD Display

                        Metal heating degasser                                                Degassing level vacuum gauge

The degassing level must be high vacuum anti pollution degassing level

 (it must pass the following "four verification of degassing level")

[Vacuum degree verification]: the imported standard sample of microporous molecular sieve can achieve the treatment effect of certificate for 8 hours in 3 hours, and high vacuum degree is the basis of high treatment efficiency.

[Pumping speed verification]: water can be pumped into ice. This method is an easy way to verify whether it is high pumping speed and high water removal capacity. High pumping speed is the premise of obtaining high vacuum degree.

[Anti flying verification]: the anti flying ability is the guarantee of the reliability of the instrument.

[Anti pollution verification]: after misoperation and flying, the vacuum degree and air tightness of the instrument will not be affected, and it can work normally.

The ability of preventing misoperation is the guarantee of low failure rate. Note: degassing system that does not support "four verification of degassing level" is not suitable for microporous material test

Analysis and test system:

Test range:

Specific surface 0.0005m2/g to no upper limit;

Pore diameter: 0.35-500nm (micropore routine analysis: 0.35-2nm;

Mesopore analysis: 2nm-50nm;

Macropore analysis: 50nm-500nm;

Total pore volume: 0.0001cc/g to no upper limit.

Measurement accuracy:

Specific surface area repetition accuracy ≤± 1.0%,

The most possible aperture repetition deviation ≤ 0.02nm,

True density ≤± 0.04%;

Surface area ≤± 1.5%.

Analysis station:

1 or 2 analysis stations are optional; independent P0 station: it has independent saturated steam pressure (P0) test station to ensure high accuracy of partial pressure test.

Test system:

According to the "national standard", use "helium" to test the volume of temperature zone, so that the test accuracy is higher and the repeatability is better. In addition, the volume of temperature zone can also be obtained through "nitrogen" test (disadvantage: using nitrogen to test the volume of temperature zone may cause part of the sample hole to be filled with nitrogen during the test process, which may affect the actual adsorption capacity of nitrogen during the test process and the test accuracy).

Gas path system:

The best "module" manifold system created by the instrument integrates the reference cavity and control valve as a whole, without any thread seal, pipeline crimping or welding interface, reduces the vacuum pipeline by more than 90%, completely eliminates the air leakage point, the air leakage rate of the whole system is less than 10-10pa * m3 / s, and the tightness is improved by 10% More than times, reaching the level of imported high-end instruments, greatly improving the stability and accuracy of instruments;

All parts of the gas system are assembled in a modular way, which greatly reduces the failure rate and enhances the stability of the instrument.

Tube diameter:

Large diameter is the necessary condition of high vacuum. The valve and pipeline with large diameter are used in degassing position and testing position, so that the ultimate vacuum of vacuum pump can get the maximum effect.

Control system: combination valve (solenoid valve + pneumatic valve) must be used to realize zero heating, and single solenoid valve cannot be used.

Vacuum system: the instrument is equipped with two independent vacuum systems, i.e. degassing system and analysis system are independent of each other, which completely eliminates the interaction between analysis and degassing at the same time and avoids the pollution caused by one vacuum system.

Pressure measurement:

Original imported capacitive membrane pressure sensor, sectional test: 0-1000torr, 0-10torr (optional); reading accuracy error ≤ 0.15%, which is the highest accuracy of the current pressure sensor; micropore section partial pressure P / P0 can reach 1 × 10-6, points are more than 50; large hole section has the real-time test function of P0, so that the control accuracy of P / P0 at the critical point reaches 0.998. Vacuum pump: original imported (Atlas Copco, formerly Edward, UK) two-stage mechanical vacuum pump, automatic start and stop control of the whole process software, realizing full automatic operation.

Liquid nitrogen Cup: Equipped with 3L large capacity and small caliber glass liner Dewar bottle, the heat preservation performance is greatly improved compared with the open stainless steel liner, the heat preservation time is more than 140 hours, and it can be tested continuously for more than 90 hours without adding liquid nitrogen, so it can meet the requirements of microporous long-term test.

                     3L liquid nitrogen dewar                                     Pressure sensor

Liquid level control:It is necessary to support the automatic replenishment of liquid nitrogen, and completely eliminate the abnormal isotherm caused by the volatilization of liquid nitrogen. Beishide's original liquid nitrogen surface servo holding system can eliminate the dead volume change caused by the change of liquid nitrogen surface due to the volatilization of liquid nitrogen during the test process, and improve the test  accuracy;

Calibration gas: equipped with 99.999% high-purity HE; with he dead volume test function and temperature zone test function; can obtain higher accuracy.

Test gas: high purity nitrogen and various gases can be selected according to the user's needs, such as CO2, AR, Kr, etc., equipped with multiple independent air inlets.

Sample type: powder, particle, fiber and sheet materials, which can be put into sample tube.

PS series specific surface and aperture analyzer --Technical features and advantages

The original modular pipeline design of integrated "modular" manifold system reduces the vacuum pipeline by more than 90%, improves the air tightness of the instrument by 10 times, and greatly improves the stability and accuracy of the instrument;

All parts of the gas path system are assembled in a modular way to reduce air leakage, facilitate troubleshooting and maintenance, and greatly enhance the stability of the instrument

The control system must adopt combination valve (solenoid valve + pneumatic valve) to realize zero heating, instead of single solenoid valve. The combination application of original imported (SMC) air control valve and solenoid valve is adopted. The switch of the air control valve is controlled by the solenoid valve. The air control valve is directly connected with the module pipeline, and the switch action of the air control valve is not heated. The problem of gas heating and expansion caused by the heating of the solenoid valve is completely eliminated.

It must be a stainless steel P0 pipe with thermal insulation structure. It is not allowed to use glass P0 pipe or ordinary stainless steel P0 pipe

(1) with independent saturated vapor pressure (P0) test station to ensure high accuracy of partial pressure test. (the static method is the saturated vapor pressure testing device of the surface and aperture analyzer, patent No.: zl201120136959. X)

(2) the spiral P0 tube is used as the saturated vapor pressure tube, which is connected with the main engine of the instrument, and can reach the liquid nitrogen temperature faster. The saturated vapor pressure of the test is closer to the real value (the effect of the imported isothermal clamp is the same, and the straight stainless steel P0 is solved The tube test results are 2% larger than that of the tube test results).

(saturated vapor pressure spiral P0 tube and static method specific surface and aperture analyzer, patent No.: zl201620716311.2)

The automatic capping function of the liquid nitrogen cup has the automatic capping function of the liquid nitrogen cup, which can effectively reduce the volatilization of the liquid nitrogen, and also avoid the condensation and freezing of water vapor on the dewar cup mouth and the sample tube (Patent No. ZL 201420148358.4 of the capping device of the static method specific surface and aperture analyzer)

The static method specific surface and aperture analyzer reference chamber thermostat with reference chamber thermostat can make the temperature of reference chamber and internal gas, valve, pipeline, sensor, etc. in the thermostat slightly higher than the ambient temperature and ensure Keep the temperature unchanged, reduce the temperature heterogeneity caused by valve heating; ensure the temperature of key components is constant, reduce the drift phenomenon of sensor, improve the accuracy, stability and test accuracy.(Patent No. ZL 201420148783.3 of static method specific surface and aperture analyzer with reference chamber thermostatic device)

There are many measures for non barrier anti flying and anti pollution:

Measures ①: the non barrier hardware anti pollution device based on the principle of vortex dust reduction, combined with the software anti pumping program, can completely eliminate the phenomenon of evaporation boiling of volatile samples in high vacuum, so as to avoid the situation that the system air tightness drops after volatile pollutants pollute the valve pipeline, as shown in the right figure;

Measures ②: the original degassing position filter bag combined with the hardware anti pumping device based on the principle of vortex dust reduction created by beishide can realize the dust filtering function without reducing the current gas flow guide, completely eliminate the pollution of powder samples to the internal structure of the instrument, shorten the time of vacuum degassing and improve the degassing effect;

Measure ③: the program-controlled step-by-step pumping speed is automatically switched to prevent the sample from flying in the instant of high vacuum;

Measure ④ :the program temperature is raised to prevent the sample from rising violently, elutriating and boiling;

Measures ⑤: after degassing, the program-controlled automatic backfilling of nitrogen; the original anti pollution filter bag combined with the principle of vortex dust reduction hardware anti pumping device, which can realize the dust filtering function without reducing the existing gas flow guide, completely eliminate the pollution of powder samples on the internal structure of the instrument, shorten the time of vacuum degassing and improve the effect.

Optional processing mode

There are two kinds of modes of sample pretreatment, i.e. "common mode" and "molecular displacement mode" initiated at home and abroad.

(purification pretreatment device of static method specific surface and aperture analyzer, patent No.: zl201120136943

Liquid nitrogen addition

Wireless electric turbine liquid nitrogen pump shall be equipped for liquid nitrogen addition to facilitate liquid nitrogen transfer from liquid nitrogen container to Dewar cup

Automatic start stop management of vacuum pump

The vacuum pump automatic start stop management optimized vacuum pump start stop management system, in the test process, the vacuum pump does not need to be in operation all the time to reduce noise and extend the life of the vacuum pump.

Automatically save current data in case of power failure

Power off automatically saves the current data with super stability. Even if the power is cut or disconnected accidentally, the current data will not be lost, and the experiment can resume.

User friendly operation interface

The user-friendly operation interface is a graphic control interface with clear image, and all hardware control operations can be carried out on the interface.

Sealing inspection

Advanced intelligent self-test process of sealing self-test, intelligent judgment of whether the sample tube is installed and whether the tube jacket is tightened for air leakage.

High intelligent working mode

The interactive data processing software of high intelligent working mode can realize the full-automatic operation of the instrument. The long-term experiment does not need the manual watch, and the report content can be customized according to the user's needs.

Prevent accidental drop of liquid nitrogen cup

Prevent the accidental drop of liquid nitrogen cup. It has the only intelligent control mechanism in China to prevent the accidental "safe drop" of liquid nitrogen cup. It completely avoids the risk of the accidental drop of liquid nitrogen cup and the explosion of sample tube caused by the expansion of gas.