3H-2000A / BET-A specific surface area tester advantages characteristics explained in detail

The 3H-2000A and 3H-2000BET-A intelligent automatic nitrogen adsorption specific surface area tester is a new product launched in 2008. It inherits the advantages of the first 3 models of the 3H-2000 series and obtains mechanical and software performance. After a substantial improvement, only the detailed description of the advantages of this model is as follows:

1. [Wind-heat removal aid device] It is the first and only program-controlled wind-heat removal aid system in China. After full automation, it can ensure sharp and rapid desorption peaks and reduce background errors. (Patent No. 5)
When the sample is heated to desorption after being saturated with liquid nitrogen at -195.8 ° C, the temperature needs to be rapidly increased to rapidly desorb the nitrogen adsorbed on the powder surface into the detector; as shown in the figure below, high-speed desorption can make The signal is concentrated to obtain sharp and sharp desorption peaks, which is helpful to improve the sensitivity and resolution of the instrument. In addition, the sharp and sharp desorption peaks can reduce the influence of background noise and improve the accuracy of the instrument test. The sharp desorption peaks are chromatographic work The ideal peak shape pursued by the person. In the previous semi-automated instruments, the artificial replacement of the liquid nitrogen cup with a water cup is usually used, and the sample temperature is quickly increased to normal temperature by using the characteristic of the large specific heat of water. However, in fully automated instruments, if auxiliary heating desorption is abandoned, natural Heating desorption, due to the low thermal conductivity of glass and slow heating, will make the desorption peak short and wide, reduce sensitivity and resolution, increase the influence of background noise, and lose test accuracy. Domestic similar instruments use natural heating desorption.

The 3H-2000A / BET-A specific surface area tester has the only program-controlled wind-heat assisted desorption device in China, which improves the desorption speed, shortens the peak out time, and sharpens and sharpens the desorption peak, which is much higher than similar instruments. Resolution and test accuracy

2. [In-situ purge function] The specific surface area tester instrument has the only integrated purge device (non-split type) in China, which solves the problem of degassing and testing integration, and realizes the in-situ treatment of the sample in one time. Installation, zero contact with air, to ensure the efficiency and effectiveness of sample pretreatment; (Patent No. 4)

The instruments before 3H-2000II and similar domestic instruments do not have the in-situ purge function; the sample purge process needs to be installed on the purge furnace that is separate from the main unit. After the process is completed, it is removed and then reinstalled on the main unit of the instrument test. 3H-2000BET-A has an integrated purge processing system that has two advantages over a split purge furnace: one is easy to operate, only needs to be installed once; the other is better processing effect, avoiding the sample when disassembling the sample tube Contact with air again; (For some organic and biological powder materials, the moisture content percentage may be relatively large, if it exceeds 2%, it needs to be oven dried before purging, otherwise purging is required And reweigh it later;)

3. [Purge timing function] The specific surface area tester has the only domestic purge procedure timing function with a timing accuracy of 1 second. After the countdown is completed, the heating power is automatically cut off and a sound prompt is given;

Purge program timing, stop heating at the time, and sound prompt. This function makes the purge processing conditions uniform, and also makes the operator more at ease in other tasks, without worrying about purge timeout, and is conducive to ISO standardization.

4. [Chromatography partial pressure detection] It has the first and only chromatographic nitrogen partial pressure detection system in China, which makes the nitrogen concentration control accuracy and detection accuracy reach one ten thousandth, and is within the full range. It is traditionally detected by the flow ratio (the imported Hollingwell sensor's full-scale accuracy is 0.5%) 10 times the concentration and has extremely high stability. The nitrogen partial pressure test is the key to the accuracy of the BET multi-point method; ( Patent No. 3)

In the multi-point method test of the BET specific surface area tester, the nitrogen concentration needs to be adjusted from 5% to 30% according to the BET theory. Nitrogen concentration detection is the key link in the accuracy of the BET specific surface area test results. In terms of nitrogen concentration test, when the nitrogen concentration is measured by measuring the flow of nitrogen and carrier gas separately, the nominal limit accuracy of the imported Hollingwell flow sensor is 0.1-0.5ml / min, for 5ml / min The highest accuracy of the nitrogen flow rate test can only reach 2%. 3H-2000BET-A type specific surface area tester dual thermal conductivity cell detector, using a chromatographic concentration sensor thermal conductivity cell to directly test the nitrogen concentration, the accuracy can reach 0.01%, and is not affected by the flow rate; Type parts, 3H-2000A type does not have this part)

5. [Gas Purification Cold Trap] It has the only domestic gas purification cold trap function, which can improve the gas purity by more than 10 times;
(Patent No. 0)

The purity of high-purity nitrogen and high-purity helium used by the specific surface area tester is generally 99.99% to 99.999%, of which 0.001% -0.01% of impurity gases (mainly high-boiling easily adsorbable gases such as moisture) will be the first when adsorbed at low temperature It is adsorbed, which affects the amount of nitrogen adsorbed; for example, the amount of water remaining on the surface of the powder within 120 minutes at a flow rate of 30ml / min is 0.14ml (volume under standard conditions), and for a 500mg material with a specific surface area of ​​1m2 / g The amount of water vapor required for the adsorption of the monolayer forming water on its surface is: 0.069 ml (standard condition), which is equivalent to the amount of water actually staying on the surface of the powder, the surface of the material has been saturated with water; if not treated, the test results It will be impossible to be accurate.

The cold trap is an effective way to eliminate high-boiling gas impurities; the cold trap allows high-boiling impurities such as water that will be adsorbed by the sample to be captured by the cold trap in advance, making the purified high-purity nitrogen and high-purity helium gas moisture The content is lower than 10-17Pa, reaching ultra-high purity gas state;

The 3H-2000A / BET-A specific surface area tester is the only specific surface area tester equipped with a cold trap device at home and abroad; this is also one of the factors that this series of instruments can achieve high precision and high resolution.

6. [Detector thermostat] It has the first and only detector thermostat system in China, which can suppress the temperature drift of the detector and ensure the accuracy and stability of the test results; (Patent No. 9)

The chromatographic specific surface area tester uses a thermal conductivity cell as the detector; temperature drift is the main cause of error in the thermal conductivity cell detector. Generally, the detectors of high-precision chromatographs have complex constant temperature systems and temperature drift suppression elimination systems, but at the same time Increase the cost of the instrument; the 3H-2000A / BET-A type is the only domestic thermostat device with a detector, which reduces the zero drift from 1% to 0.1%. This device is particularly effective for testing small specific surface area samples (<10m2 / g) ;

7. [Programmable six-port valve] Programmable six-port valve calibration system, the action cycle is less than 0.01 seconds, which is one-tenth of the action cycle of the traditional six-port valve; The six-way valve does not have this function; (The device is a 3H-2000BET-A type part, 3H-2000A type does not have this part)

The six-port valve is the main calibration device for quantification of chromatographs. There are manual six-port valves and electric six-port valves. 3H-2000BET-A has a program-controlled electric six-port valve calibration system, which is fully automatically controlled by the calibration process software. The only optional function of quantitative tube volume program control; for different samples, the specific surface may be thousands of times different from each other, and the amount of nitrogen absorbed is also very different. It is impossible to calibrate the adsorption capacity of all samples with one volume of quantitative tube. Therefore, the calibration system should be connected to quantitative tubes of different volumes to achieve higher accuracy. The automatic calibration device of domestic similar instruments does not have the optional function of quantitative tube volume program control. The replacement of the quantitative tube volume requires manual replacement or even opening of the casing for replacement. The 3H-2000BET-A specific surface analyzer can be programmed to switch quantitative tubes with different volumes.

8. [LCD liquid crystal display] The large-screen 5-inch LCD liquid crystal display makes the working status parameters of the instrument clear at a glance, and the working parameters of the instrument are displayed on the software and the LCD liquid crystal screen at the same time, making the instrument more stable;

The main parameters of the instrument are not only detected and displayed on the software, but also displayed on the LCD hardware display of the instrument. Even when the computer is not turned on, the instrument status can be clearly grasped, making the instrument more reliable;

In addition, the instrument's gas flow rate, motor, desorption fan, purge timing, air source switch status, etc. all have hardware indicators to indicate the working status. The status of each part of the complex equipment is working normally or not. It is necessary to make hardware instructions; reliable modern analytical instruments can have only one control button, but the operation status indication of various parts such as display screens and indicator lights cannot be saved;

9. [Liquid Nitrogen Temperature Detection] Real-time monitoring of liquid nitrogen temperature to eliminate the influence of temperature difference of ordinary industrial liquid nitrogen, and the use conditions are wide;

The liquid nitrogen used in the specific surface test is purchased by the nearest unit, and is generally a by-product of oxygen production in a gas plant. Its purity instability varies greatly, so that the temperature of the liquid nitrogen varies by about 1 ° C; the amount of nitrogen adsorption on the liquid The change of nitrogen temperature is very sensitive; in addition, the level of the liquid nitrogen surface in the liquid nitrogen Dewar also affects the adsorption capacity; the 3H-2000BET-A instrument has a liquid nitrogen temperature monitoring sensor, which can monitor the liquid nitrogen temperature and the Dewar cup. Whether the amount of liquid nitrogen is sufficient; domestic similar instruments do not have this function.

10. [Best Sample Tube] Beside sample tube, which is the exclusive patented technology in China, ensures the accuracy of the test while making the sample tube loading convenient and not limited to powder sample testing; (Patent No. X)

The sample tube used for chromatography specific surface area testing is facing such a contradiction in the domestic industry: chromatography requires that the inner diameter of the pipeline be as thin as possible to reduce the effect of turbulence; but the sample tube that is too thin makes the sample loading and practical application Cleaning is very inconvenient; Beste's sample tube cleverly uses the form of large-inlet and small-outlet sample tubes. The large-diameter end makes it easy to fill and clean the sample. The small-diameter gas outlet does not increase the turbulence effect; currently only 3H in China -2000 series specific surface area tester and instrument use Bayster sample tube;

11. [Gas cut protection] It has the only gas source switch indication and protection device in China, which can permanently avoid the damage to the detector caused by the gas cut off and live operation;

The chromatograph generally requires the operator not to turn on the power when the gas is not turned on, that is, "turn on the gas first and then turn on the power, then turn off the power and then turn off the air." Otherwise, it may happen that the detector is energized and burned out without ventilation. Danger; and the gas source indication and protection device of the 3H-2000BET-A specific surface area tester makes this danger removed.

12. [Granularity Estimation] It is the only domestic company that has the function of data processing for estimating the particle size model and giving a particle size estimation report; this function can give the average particle size under each model based on the specific surface area;

The 3H-2000BET-A specific surface area tester is the only model in China that gives a particle size report; and 4 typical models are established in the particle size report. The operator can also set a particle size correction factor according to the surface state of the powder to make the model estimate The result agrees with the actual value to a higher degree;

13. [Full-automatic operation] Fully automatic program control of the adsorption and desorption process, and sound prompts for all important links; the operator does not need to worry about delaying the experiment when performing other work or leaving during the operation of the instrument;

14. [Powerful software system] The software is a self-developed high-precision data processing system with high sampling frequency and full automatic control; the peak shape intelligent identification function of the software can be used even when the instrument is not warmed up or when the zero drift is serious It can accurately cut out the peak area, ensuring the positive and high accuracy of the desorption peak surface; ensuring the leading position of our company's instrument accuracy in the same industry. Powerful specific surface data processing capabilities, collecting many years of experience in specific surface testing experiments, and retaining excellent functions of foreign related software, excellent performance, ensuring extremely high measurement accuracy and sensitivity, stable operation;

15. Test report: solid standard sample reference method report, particle size estimation report, BET single-point method report, BET multi-point method report, Langmuir multi-point method report, statistical specific surface area report of adsorption layer thickness method; and BET can be given Adsorption constant C, Langmuir adsorption constant b, multi-point correlation coefficient r; (3H-2000A type report is solid standard reference method report, particle size estimation report)

16. Test time: BET multi-point method, which can test 4 samples at the same time, the test speed averages about 5 minutes per sample for each partial pressure point; BET single-point method, which can test 4 samples at the same time, each test speed average The sample measurement time is about 5 minutes; the solid standard reference method can test 3 samples at the same time, and the average measurement time of each sample is about 6 minutes. The above test time does not include the sample purge purification pretreatment time.

17. The operation of the instrument is simple and easy to learn, the accessories are complete, the after-sales service is thoughtful, and the customer is wide (see the list of typical customers)

The 3H-2000 series specific surface area tester has the widest customer use in China. Best Side (formerly Huihai Hongnan) is the earliest domestic specific surface area tester manufacturer; it entered the market in 2000 and after 8 years of development Improvement to form a series of products with various models and functions; the company implements a post-sale system for all customers to visit every 3 months; the specific surface test room of our company is a number of scientific researches such as the Institute of Physics and Chemistry of the Chinese Academy of Sciences, Beihang University, North University of Technology, Mining University The specific surface of the unit specifies the test unit; the instrument is fully equipped, except for the liquid nitrogen that cannot be transported, all accessories including sample tube cleaners and protective equipment;

The company's excellent instrument performance and good after-sales service have made many customers choose our 3H-2000 series instruments in the purchase after many years of use. For example, Ningxia Dongfang Tantalum purchased one in 2001, one in 2009, and 2010 Purchased 2 units per year; Qingdao Taineng Graphite purchased 1 unit in 2004 and 1 in 2006; Zhengzhou University of Light Industry purchased 1 unit in 2005 and 1 in 2007; 4 units from Tianjin University, 2 units from Nanjing University of Technology and Qingdao Gaoer 2 sets of graphite-rich, 2 sets of Qingdao TEDA graphite, etc. For other customers, please refer to "Typical Customer List";

Mark of high-precision dynamic chromatography specific surface area tester:

1. Whether there is an in-situ purge processing device; (improve pretreatment efficiency)

2. Whether there is a desorption assisting device; (improve sensitivity)

3. Whether the quantitative tube can be switched by program control; (improve the calibration accuracy)

4. Whether the partial pressure detection of nitrogen concentration is by flow method or chromatography; (improve the precision of partial pressure detection)

5. Whether there is a low temperature cold trap; (reduce the influence of impurities in the gas)

6. Whether it has the constant temperature function of the detector; (suppress zero drift)

7. Whether it has the function of liquid nitrogen temperature detection; (eliminate the industrial liquid nitrogen temperature difference)

Manufacturers who need to purchase a specific surface area tester please contact the sales personnel of the professional manufacturer of specific surface area tester-Best Instrument Technology (Beijing) Co., Ltd.