manufacturer :       Micromeritics

model :                   Gemini 2380

annotation :           Dokumente engl.

Description

The Micromeritics Gemini V Series of surface area analyzers utilizes a patented twin-tube design which assures fast and accurate dosing of the adsorptive gas without pressure overshoot. Paired with the extended capabilities of the embedded software and the powerful new Windows control option, data archiving, and reporting software option, the Gemini V Series offers an extended range of capabilities, and is capable of performing measurements on materials with low surface area without requiring the use of krypton.

For applications that fall under FDA’s 21CFR11 rule, the Gemini V Windows confirm™ software option provides the security features and audit trails required by this regulation.

The Gemini V Series of surface area analyzers uses the Static Volumetric Technique to generate high-speed surface area and porosity data ..

Features

• Fully automatic operation
• High throughput
• Windows ^® driven software (optional)
• Choice of analysis mode (scan or equilibrate)
• No pressure overshoot
• Common mode rejection of free space error effects
• No gas flow integrator required
• 21 CFR 11 Software Option
• English, French, German, Italian and Spanish language options
• IQ/OQ Validation service (optional)

Gemini V Models
There are two models in the Gemini V Series, enabling you to get the analyzer that best suits your specific needs. Capabilities are further expanded on each model if the Windows software option is included.

Gemini 2365
The Gemini 2365 determines single-point and multipoint BET and Langmuir surface areas, total pore volume, and micropore analysis by the t-method. Also included is the capability to determine statistical thickness surface area (STSA) of carbon black (refer to ASTM D 6556, ASTM D 3765, ISO/DIS 18852.2, or ISO/CD 4652-2/3).

Gemini 2380
The Gemini 2380 has all the abilities of the Gemini 2365 and additionally can provide BJH pore volume distributions. Up to one thousand isotherm data points may be collected.

Specification

Analysis Technique

The Gemini uses an adaptive rate, static volumetric technique of operation. It is the first gas sorption method which adapts the required rate at which gas is supplied for equilibration. The Gemini has, as illustrated in Figure 1 (below), two gas reservoirs (A) which are filled with equal volumes of the desired adsorptive, usually nitrogen. From the reservoirs, gas is dosed into the sample and balance tubes. A transducer (B) on the sample side monitors for the target pressure. As the sample adsorbs gas, the pressure would tend to decrease in the sample tube were it not that transducer (B) causes a fast response servo valve (C) to hold the pressure constant. Transducer (D) located between the sample and balance tubes detects any pressure difference between the two tubes and causes another servo valve (E) to balance the pressures in both tubes. A third pressure transducer (F) monitors the pressure between the two reservoirs to determine the amount of gas that is adsorbed on the sample. This method of dosing and accounting for the volume of gas uptake enables the Gemini to produce highly accurate, highly reproducible results in the minimum time.

Twin-tube design
The sample and balance tubes are identical in every way. Conditions within one tube exactly reproduce the conditions within the other, the only difference being associated with the presence of the sample in the sample tube. Free-space errors introduced by thermal gradient variations are canceled because the balance tube essentially has the same free space variation as the sample tube and no pressure differential is produced. Since free-space error is the limiting factor in measuring low surfaces with nitrogen, common mode rejection of free-space variation in the Gemini allows accurate measurements to be performed on low surface area materials that by other static volumetric techniques would require the use krypton.

Accelerated dosing of the analysis gas In the unique Gemini design, the sample uptake rate controls the rate at which the gas is delivered through a servo valve, therefore the adsorptive is delivered as fast as the sample can adsorb it. In this manner of dosing, there is no under-dosing in which the sample waits for more adsorptive, nor over-dosing in which case the target pressure is exceeded. The result is a surface area analyzer that is as fast as the physics of adsorption allows and yet retains accuracy and reproducibility. Gemini analyzers can be operated from the keypad (included with the analyzer) or, optionally, from a computer. Using computer control, you can operate up to four Geminis simultaneously from a single computer.

Two categories of software control

Embedded software: The Gemini V Series continues to be a stand-alone physical adsorption analyzer. The Gemini V Series offers two versions of embedded software that allow the unit to be operated without the need for an external PC. Each Gemini V embedded software version provides a wider range of analysis choices and data reduction capabilities than in previous Gemini models.

Intuitive and powerful Windows-based software :
The optional Windows-based software allows the Gemini V Series to be controlled from a PC, thus providing more versatility in data archiving, networking, and printer options. In addition, the Windows software extends the choices of data reduction methods in each Gemini model.

For applications that fall under FDA’s 21CFR11 rule, the Gemini V Windows confirm™ software option provides the security features and audit trails required by this regulation.

Windows Option Software Features
The easy-to-use Gemini software utilizes a Windows interface to help plan, launch, and control the analysis. You can collect, organize, archive and reduce raw data, and store standardized sample information and analysis conditions for easy access during later applications. Features include cut-and-paste graphics and tables, scalable-and-editable graphs, and customizable report formats.

Windows Option Analyses and Reports
The new Gemini Windows software includes powerful data reduction software.

• Single- and Multipoint BET (Brunauer, Emmett, and Teller) surface area
• Langmuir surface area
• Pore volume and pore area distributions in the mesopore and macropore ranges by the BJH (Barrett, Joyner, and Halenda) method using a variety of thickness equations including a user-defined, standard isotherm (2380 model)
• Pore volume (distribution and total pore volume) in a user-defined pore size range
• Micropore distribution by the MP-method (2380 model) and total micropore volume by the t-Plot and as Plot methods
• Halsey, Harkins-Jura, Carbon Black STSA, Broekhoff-de Boer and user-entered thickness curves

The 2380 model also includes

• Dubinin-Radushkevich (D-R)
• Dubinin-Astakhov (D-A)
• Fixed pore size tables
• Linear & Log Plots (isotherm, pore volume, pore area)
• Cumulative and Differential data
• Plot overlays, any type

21 CFR Part 11 Option
Also available is confirm™ software, which addresses the many requirements specified by 21 CFR Part 11 validation, security, audit trails, reporting, and more.