RGA120 Series Residual Gas Analyzers

The 120, 220 and 320 amu residual gas analyzers from SRS offer exceptional performance and value. These RGA's provide detailed gas analysis of vacuum systems at about half the price of competitive models. Each RGA system comes complete with a quadrupole probe, electronics control unit (ECU), and a real-time Windows software package that is used for data acquisition and analysis, as well as probe control.

Rugged Probe Design

The probe consists of an ionizer, quadrupole mass filter, and a detector. The simple design has a small number of parts which minimizes outgassing and reduces the chances of introducing impurities into your vacuum system. The probe assembly is rugged and mounts onto a standard 2.75" Conflat flange. It is enclosed within a stainless steel tube, with the exception of the ionizer which requires just 2.5" of clearance in your vacuum system—about that of a standard ion gauge. The probe is designed using self-aligning parts so it can easily be reassembled after cleaning.

Compact Electronics Control Unit

The densely packed ECU contains all the necessary electronics for controlling the RGA head. It is powered by either an external +24 VDC (2.5 A) power supply or an optional, built-in power module which plugs into an AC outlet. LED indicators provide instant feedback on the status of the electron multiplier, filament, electronics system and the probe. The ECU can easily be removed from the probe for high-temperature bakeouts.

Unique Filament Design

A long-life, dual thoriated-iridium (ThO₂/Ir) filament is used for electron emission. Dual ThO₂/Ir filaments last much longer than single filaments, maximizing the time between filament replacement. Unlike other designs, SRS filaments can be replaced by the user in a matter of minutes. Improved filament protection checks process pressure before turning on the filament.

Continuous Dynode Electron Multiplier

A Faraday cup detector is standard with SRS RGAs, allowing partial pressure measurements from 10^-5 to 5 × 10^-11 Torr. For increased sensitivity and faster scan rates, an optional electron multiplier is offered that detects partial pressures down to 5 × 10^-14 Torr. This state-of-the-art macro multi-channel, continuous-dynode electron multiplier (EM) offers increased longevity and stability, and can also be replaced by the user.

Automatic Peak Tuning

Efficient RF generation with dynamic RF resonance frequency tracking is used to provide increased mass range. It also enables automatic peak tuning using independent RF/DC control, while increasing scan speeds up to 130 AMU/s (260 AMU/s with 10 points per AMU).

New Hybrid Electrometer

A wider dynamic range hybrid electrometer works as a linear amplifier with low current (<1 nA) and as a log amplifier with higher current (up to 2 uA). At low or negative current values, the linear mode leads to improved baseline sensitivity

This temperature-compensated, hybrid log electrometer detects ion current from 10^-7 to 10^-15 amps in a single scan, with better than 2 % precision. This huge dynamic range means you can make measurements of small and large gas concentrations simultaneously.

Built-in I/O

A rich set of input/output connections provide monitoring and control of the RGA, and also enable external process control. An external scan trigger, a configurable event based relay, GPIO, and an RTD input for temperature monitoring during scanning are included. An analog output provides a signal proportional to any scanned variable, including partial pressure.

Complete Programmability

Communication with computers is made via USB, Ethernet or RS-232 interfaces. Analog and histogram (bar) scans, leak detection and probe parameters are all controlled and monitored through an extensive SCPI command set. This allows easy integration into existing programs.

RGASoft Windows Software

A brand new RGASoft Windows application is included. With a rich feature set and modern UI design, scan data is captured and displayed in real-time or scheduled for acquisition at a given time interval for long-term data logging. Multiple spectral data and individual measurements can be collected together in one sequence. Versatile docking windows and widgets give the user various ways to organize the display. Data can be scaled manually or automatically, in linear or log format on plots. Units are selectable among Torr, Bar, Pascal and Amp. Features include common gas labels, programmable audio and visual  alarms, expandable library, composition analysis, and comprehensive on-line help.

The software also allows complete RGA control with easy mass scale tuning, sensitivity  calibration, ionizer setup, and electron multiplier gain adjustment. For further analysis, data files can be saved in CSV text format for easy transfer into spreadsheets. Graphic images can be saved in common formats (PNG, BMP, TIFF, JPG, SVG, PDF) or copied to the clipboard for importing directly into other programs.

The software supports multiple head operation when more than one RGA is needed. Multiple RGAs can be controlled and run concurrently with multiple software instances. The number of RGAs is only limited by the system resources.

Performance and Value

The new RGA120 series is ideal for applications involving gas analysis, leak detection, and vacuum processing. We offer 120, 220 and 320 amu systems with supporting Windows software, and options that include an electron multiplier and built-inpower module for AC line operation. The RGA Windows software is downloadable from SRS website.