Gemini VII Series Surface Area Analyzer from Micromeritics

The Gemini VII 2390 Series of surface area analyzers available from Micromeritics are low-cost and simple-to-use instruments that can instantly create precise results on surface area and porosity. The robust and reliable systems are used in laboratories across the globe and are commonly employed in research and quality control settings.

The novel use of sample and balance tubes is the secret behind Gemini’s exceptional capabilities. The sample and reference reservoirs are identical like their related tubes and are charged to the same pressure. The tubes are also similar in every aspect. The differential pressure between reservoirs is checked during an analysis. This common mode of method makes certain that any differential pressure is only attributed to adsorption by the sample and not to factors that cause changes in free space during an analysis.

Key Features

The product features of the Gemini VII Series Surface Area Analyzer are:

• The Windows version includes installation videos and system verification tests to assure high performance and reliability.
• Allows low surface area measurements without needing krypton by reducing free-space error
• The twin-tube design counteracts free-space mistakes caused by thermal gradient differences or by initial mis-measurement of free space
• Speeds up delivery of the analysis gas as sample uptake controls the speed at which the gas is supplied to the specimen
• Using servo valve to control the speed of gas flow within the sample tube ensures precise achievement of target pressures without causing pressure overshoot
• Three options of software control are available

Advantages of the Gemini VII 2390 Series

• Fully automatic operation
• System verification tests
• Low cost
• High throughput - up to four Geminis can be used with single PC
• Computer or keypad--operated with Windows-driven software
• Can measure low surface area materials
• No pressure overshoot
• No thermal-diffusion errors
• Choice of analysis mode (scan or equilibrate)
• Common mode rejection of free-space error effects
• 21 CFR Part 11 software option
• Optional stainless-steel Dewars
• Optional IQ/OQ validation service

Model Options

• Gemini VII 2390a - Ideal for rapid and accurate surface area determinations by single-point and multipoint BET and Langmuir methods. In addition, provides standard methods for total pore volume, micropore analysis by the t-method, and much more. Included is the capability to determine statistical thickness surface area (STSA) of carbon blacks. (Refer to ASTM D 6556, ASTM D 3765, ISO/DIS 18852.2, or ISO/CD 4652-2/3.)
• Gemini VII 2390p - Provides additional precision with the addition of a saturation pressure (P0) tube that allows the system to monitor the saturation pressure of the adsorptive on a continuous basis during an analysis. This design feature permits a rapid measurement of the adsorption isotherm to near-saturation, as well as determination of pore size distribution.
• Gemini VII 2390t - Has all the ability of the 2390p, including a P0 tube, with the addition of a larger Dewar and longer sample tubes for extended analyses. This provides the additional capability to measure the total adsorption-desorption process. With this data set, one can perform a BJH or Dollimore-Heal pore size distribution using up to 1000 data points.