Residual Gas Analyzer

Includes built-in ion and pirani gauges

Models XT100, XT200, XT300

Prices starting at $3450.00

The XT residual gas analyzer (RGA) from Extorr offers exceptional performance and value. These RGAs provide a more detailed vacuum gas analysis than is offered by any other single competitive device. Each system comes complete with a multi-gauged quadrupole probe, a control and communications unit (CCU), and a real-time Windows® software package.       

  • Residual Gas Analyzer with Integrated Pirani and Ion Gauge
  • 100, 200 and 300 amu systems
  • Faraday Detector with optional Electron Multiplier                                  
    Compact Design
  • Real-time Windows® software capable of Multi-head operation
  • Field Replaceable Dual Thoriated Iridium Filaments
  • Better than 1 amu resolution
  • 8 orders of magnitude dynamic range in a single scan
  • Mass spectra, leak detection and pressure vs. time modes
  • Built in Diagnostics, Easily upgradeable Software and Firmware
  • Fully Insertable Probe

Performance and Value

The Extorr XT Quadrupole RGA systems are ideal for applications involving gas analysis, leak detection and vacuum processing. An Extorr RGA is often the only vacuum gauge that your system will require. This combination of flexibility and competitive price makes the Extorr your best vacuum measurement value.

The Vacuum Plus Feature

The XT systems come with built-in Pirani and Bayard-Alpert type ion gauges. The Pirani gauge is built into the base of the probe and is integrated with the software and CCU (Communications and Control Unit) to measure the early pump down pressures of a rough vacuum. The Pirani gauge is also used to regulate the startup of both the ion gauge and the Quadrupole for partial pressure measurements. The Pirani gauge also performs the critical functions of protecting the filament and the electron multiplier by recognizing when the system is in an over-pressure condition. The ion source end of the probe acts as a high efficiency ion producer for both the quadrupole mass filter and for a high quality Bayard-Alpert gauge. So intermediate vacuum pressure, total vacuum pressure and partial vacuum pressure may be measured using a single Extorr probe. There is no longer a need for any other vacuum gauge for your system.  more about the B/A, pirani


Unique Probe Design

About the Vacuum Probe

The probe consists of an ionizer, quadrupole mass filter and detector. While adhering to the most stringent ultra high vacuum standards, the novel design optimizes RGA, Pirani and ion gauge performance. The rugged probe assembly mounts onto a standard 2 3/4 inch CF flange. The end of the probe extends 6.8 inches (173 mm) from the mounting flange face. It requires no added vacuum extension nipple. Such a nipple (Extorr model number N-500) may be used give the user a required clearance in the vacuum system. The probe is designed using self-aligning parts and may be easily reassembled after cleaning.



Compact Communications and Control Unit

The densely packed CCU contains all the necessary electronics for RGA probe control and for computer communications. An RS-232 COM port is used to communicate to the host computer and the baud rate can be chosen in the software. The 115,200 baud setting is normally used except with very long cables or in noisy environments. USB to COM port adapters function well on computers such as inexpensive laptops that do not have the serial COM ports. Placing the adapter at the  computer end of the communication cable will free the user from the 5 meter limit on USB cable length and poor USB noise immunity. The CCU is powered by +24 VDC (2.1 A). This power may be supplied using the wall plug unit that comes with each XT unit at no extra cost. The CCU can easily be removed from the probe for high temperature bake-outs. The firmware is automatically updated with new software versions. The complete status of the probe is reported back to the computer This status report, including the probe temperature, the CCU temperature and the voltages on the probe elements is continuously read back to the host computer and may be used for diagnostic purposes.

Long life filaments

Long-life thoria coated iridium filaments are used for both RGA and ion gauge operation. The filament assembly is composed of two thoria coated iridium filaments, The filament supply in the CCU constantly monitors the filament resistance. When one of the filaments finally evaporates and fails, the resistance increases, warning the user to replace the filament assembly before electron emission becomes unavailable. This filament assembly is protected against vacuum excursions by both the ion and Pirani gauge functions. Because of this protection, filaments will last far longer than filaments in competitor's RGA units. Extorr filaments are easily replaceable in the field. The replacement can be done in minutes, and for less than $100.


Sensitive Faraday Ion Detection

A Faraday cup detector is standard with 100, 200 and 300 amu systems. The ultra-sensitive, wide dynamic range amplifier detects ion currents from 10-6 to 10-15 Amps automatically. This allows partial pressure measurements from  10-4 to 10-11 Torr. This huge dynamic range means you can make measurements of small and large gas partial pressures in a single spectral scan. Since this same amplifier is used in conjunction with the electron multiplier when present, partial pressure measurements to below 10-14 Torr are possible.

Ultra Sensitive Electron Multiplier Detection

A robust Electron Multiplier detector option is available for all XT systems. This detection enhancement system operates by converting each ion into an avalanche of electrons. This results in a current amplification which may approach a million. Practical amplifications of a thousand to ten thousand can increase instrument sensitivity by an equal amount. Perhaps most importantly, a desired spectral signal to noise ratio may be achieved in less than 1/1000 of the time as for the equivalent Faraday detector scan. The XT100M, XT200M, and XT300M come with the electron multiplier detection installed. As a field installable upgrade, the multiplier detection system may be added to any of Extorr’s 100, 200 and 300 amu systems. The multiplier field upgrade requires that a high voltage mini-module be placed into the CCU electronics and Extorr’s continuous dynode multiplier be easily placed into the probe by hand. The current VacuumPlus software supports both detection systems. The Extorr “all is measured, all is protected” policy extends to the multiplier detection system. Just as for the ionizer filament and the RF, the built-in Pirani and BA ion gauge protect the multiplier against over pressure. For non-interfering portions of the residual gas spectrum, the multiplier detection system allows for partial pressure readings of lower than 10-14 Torr.

Complete Programmability

Partial pressure spectral scans, partial pressure trends, audio leak detection, true total pressure measurement, and probe operating parameter modification are all features that are standard with Extorr XT systems. The intuitive nature of the Extorr Windows® computer environment makes for rapid system utility for both the seasoned RGA user as well as for the novice. Simplicity of communication makes for easy integration into existing computer vacuum control systems.

Extorr Vacuum Plus Windows Software

All Extorr systems come with VacuumPlus, a real-time Windows® software package at no extra cost. An intuitive graphical user interface makes the total functionality of the Extorr system available to the user. This starts with the first Pirani measurements, and continues on to ion gauge measurements and RGA partial pressure measurements. Complete pump down may be monitored both quickly and easily. The VacuumPlus program is fully interactive giving the user complete control of the graphical display. A number of graph or table windows may be opened, simultaneously, for monitoring multiple XT units. Data is captured and displayed in real-time. The user may choose to display data in torr, Pascal or amps. A logarithmic data display may be invoked so that partial pressures, which may vary by many orders of magnitude, may be displayed on a single graph. The software also allows for complete RGA probe control. There is easy mass scale tuning, sensitivity calibration, and ionizer setup. For further analysis, data files can be saved in a number of formats. Graphs may be set to a printer. Digital data may be saved in text format or an XML format for easy transfer into spreadsheets and other applications. Real-time streaming XML data is available for use in other user programs.

Exclusive Extorr Features

The Indestructible RGA with the best warranty in the industry

Extorr's residual gas analyzers set a new standard for reliability. The filament and electron multiplier are protected by the Pirani gauge. The electronic circuits are protected against probe shorts to the vacuum system walls. This allows Extorr to extend a one year replacement warranty on the entire device including the filament and electron multiplier, an industry first.

  • A solidly built vacuum probe with few troublesome screws.
  • If probe is contaminated, it is easily disassembled and cleaned.
  • Vacuum break, surprise outgassing, inadvertent vent, over pressure? No Problem!

Atmosphere to UHV measurement and leak detection

Our RGA's come with built-in Pirani and Ion gauges for complete vacuum measurement. You can do leak detection at any pressure. Extorr is the only RGA manufacturer that offers these features. RGA's are great for qualitative partial pressure measurements, but can only be used for quantitative readings when periodically calibrated against an accurate ion gauge to adjust for sensitivity changes as the ionizer ages. This is because low energy ions (5-10 EV) are needed for separation in a quadrupole mass filter. An  ion gauge uses much higher ion energies (150 EV) than the RGA ionizer and is much less susceptible to sensitivity decrease due to aging. The Extorr ionizer has two regions that produce both low and high energy ions simultaneously and two separate detectors. Other manufacturers will report total pressure readings using various schemes that use the low energy ions created in the ionizer. The problem is that the readings will also decrease as the ionizer ages. Other manufacturers tell you to calibrate using an ion gauge, but they do not give you the ion gauge.

Best form factor

  • Small size without any compromises in performance.
  • Energy efficient, uses no fan.
  • Probe is strong enough to stand on its own. It needs no support nipple and is able to penetrate deep into the vacuum chamber on a 2-3/4 inch UHV flange with no special hardware.

Isolated RS-232 makes the Extorr RGA EMI proof

The computer interface uses a robust serial, optically isolated cable to connect the CCU to the host. Communications to the host computer are continuously checked for errors and retransmitted automatically without interruption of the data collection. The baud rate can be selected up to 115,200 for high speed on cables 50 feet or less. Lower the baud rate for even more noise immunity on longer cable runs.

Snap-in Electron Multiplier with warranty

If you want to upgrade or replace your electron multiplier, simply use a clean glove and snap it out with your fingers. No tools or disassembly of the probe are required. The CCU electronics will meter out just enough current to the electron multiplier to run it properly, avoiding destructive channel current during overpressure. We are so confident in the durability of the multiplier that we give a one year warranty against any failure, except of course, physical breakage or contamination.

Extensive Diagnostics

If you do have a problem with your Extorr Residual Gas Analyzer, there is a software page that give complete diagnostic information about the probe and electronics. Over 90% of failures are able to be diagnosed and corrected over the phone or e-mail. By sending us the log from the Vacuum Plus software, we can tell exactly where the problem is and what to do about it.

The best Sensitivity and Stability

We are confident that we have as good or better quality data as any instrument in this price range, giving you the best value. Designed for ease of use, easy to maintain, easy on your wallet.