BET Specific Surface Area & Pore Size Analyzer BELSORP MAX G

Ultra-Low Pressure Measurement

The BELSORP MAX G allows for high-accuracy measurement of adsorption isotherms in a wide range, starting from the ultra-low pressure region (P/P₀ = 10^-8, N₂ @ 77 K) to atmospheric pressure. The BET surface area and pore size distribution analyzer includes a turbo molecular vacuum pump and low-voltage pressure transducer.

Innovative Free Space Measurement for Highest Accuracy (AFSM^TM)

Strictly controlling the level of liquid coolants (e.g. liquid nitrogen or argon) is no longer required with the BELSORP MAX G. Instead, we have implemented our groundbreaking, continuous free space measurement method: the patented Advanced Free Space Measurement (AFSM^TM). This method achieves the highest level of reproducibility by using a reference cell to follow the second-to-second changes of free space. First, the instrument determines the free space of the sample cell and reference cell. Then, as the analysis proceeds any changes to the system that might alter the measured Free Space are concurrent in both cells. Therefore, alterations in the measured free space can be continuously accounted for through the reference cell.

Examples of causes for free space fluctuations include:

• Liquid nitrogen (LN₂) level changes
• Atmospheric temperature and pressure changes
• Coolant temperature changes due to dissolution of oxygen

Ease of use – Simple Setting of Measurement Conditions

The BELSORP MAX G has a fully automated system that enables the user to easily setup measurement conditions through ‘Simple Mode’. This mode makes sample analysis a breeze by only requiring minimal user entry (e.g., sample information, pretreatment conditions and measurement range). This is particularly useful for unknown materials and for the application of standard operation procedures. Detailed measurement configurations can be set by experienced users by selecting the ‘Professional Mode’.

Gas Dosing Optimization (GDO)

The Gas Dosing Optimization (GDO) function calculates the optimal gas dosing amount from previous measurement results. This function can reduce measurement times significantly.

Helium-Free Measurements (AFSM^TM2)

By measuring the free space of a ‘blank’ sample tube in advance, measurements can be achieved without the need for helium gas. Using the same sample tube, in the same analysis conditions, the free space can be easily calculated using your sample’s mass and density. This method also reduces sample analysis time by cutting out the free space determination at the beginning of every sample measurement. With AFSM^TM2, there is no need to match the liquid level of the coolant between the blank measurement and sample analysis.

Compact & Lightweight

By optimizing the component materials, we have managed to provide a unit with a small footprint and low weight.

In-Situ Pretreatment (Optional)

For an accurate adsorption measurement, a pretreatment of the samples is required. The pretreatment process (also called activation process) is usually performed by applying vacuum under heat, which removes adsorbed gas and / or water molecules from the surface of the material without affecting the sample structure (avoiding denaturation).

Microtrac offers two options for sample pretreatment. First, it can be performed externally using our BELPREP equipment, which is usually preferred to increase sample throughput. Alternatively, the activation process can be performed directly at the measurement port of the BELSORP MAX G using a heater (see accessories list). This way, a transfer from the external pretreatment device to the measuring port can be avoided, which is an important option for sensitive samples (e.g. hydrophilic material).

Data Analysis

Our BELMASTER analysis software is provided with the BELSORP MAX G, and enables the user to perform a wide variety of data analysis, including evaluating specific surface areas using the Langmuir or BET method, evaluating pore volumes by applying the t-plot method, conducting mesopore analyses with the DH or BJH method, micropore analyses via HK or SF method, or GCMC / NLDFT analyses, and much more.

The versatility of the BELSORP instruments, with their many features and possibilities, is complemented by our intuitive and user-friendly operation software. It guides the user step-by-step through the analysis process including setting up the analysis conditions, executing the measurements, when to fill and setup the liquid nitrogen or other bath, when to replace the gas cylinder, the degassing steps, and much more. The software has been crafted to make the instrument accessible to everyone, even inexperienced users.

Two measurement modes are offered: ‘Simple Mode’ and ‘Professional Mode’. Simple Mode enables easy operation, requiring minimal setup. You only need to enter the basic sample information (name, mass, etc.) and then select your pretreatment conditions and analysis conditions from a list of preset options. This is ideal for inexperienced users or measurements of unknown samples. If a prior measurement with comparable sorption behavior has been performed, GDO can be used to reduce the measurement time. Professional Mode allows detailed control of the configuration and measurement settings (e.g., dosing settings, equilibrium criteria, leak-check option, etc.), allowing the user to completely customize sample analysis.