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reference comparison method

BET method

Desorbed gas calibration

Compare directly with standard sample peak area with known surface area, no need for real gas desorbed calibration.

No standard sample required, use gas peak area of known set volume to calibrate the testing samples gas volume.

　　Principle

Adsorptions peak areas of a sample and standard are proportional to their adsorbed gad volumes, respectively, therefore samples surface are can be obtained through simple comparison.

Based on multi-layer adsorption theory, single-layer saturation adsorption gas volume can be derived by BET equation for surface area calculation. BET method is the most popular nitrogen adsorption surface area testing method.

　Testing gas

                                            Fixed ratio of He to N2（4:1）

High purity N2 and He, experiment need to choose various mix ratio.

 Application range

Applicable samples which have similar adsorption performance to standards, domestically widely used in carbon black industry, not much use abroad.

Applicable to all kinds of samples without micro-pores. This is internationally accepted method for various applications.

　　Result

Test accuracy varies depending on different samples

Using standard set volume gas to calibrate nitrogen adsorption volume, this method enjoy high accuracy regardless samples varieties.

Application area

On-site product line monitoring, fast surface area testing.

Research institutes, universities, enterprises for precise surface area testing