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Binary Gas Analyzer BGA244 ... from $3950
BGA244 Binary gas analyzer with 0.1 % accuracy
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BGA244 Binary Gas Analyzer
  • Measures gas ratio of two gases, or purity of a single gas
  • Non-invasive measurements
  • <0.1 % composition error
  • Touch screen display
  • 4 samples per second measurement rate
  • USB, RS-232 and RS-422
Pure gases, and gas mixtures, are critically important in thousands of industrial and scientific processes. A new gas analyzer from SRS can quickly, continuously, and non-invasively determine the ratio of gases in binary mixtures or check the purity of a single gas.
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User's Manual
Quick Start Guide
BGAMon Software


BGA244 Binary Gas Analyzer

The BGA244 Binary Gas Analyzer quickly, continuously, and non-invasively determines the ratio of gases in a binary mixture, or checks the purity of a single gas.

It’s ideal for a host of applications including binary gas blending, PSA (pressure swing adsorption), helium recovery, ozone purity, dopants and carrier gases, and general research where precise measurements of gas mixtures are necessary.

The BGA244 operates without lasers, filaments, chemical sensors, optical sources, separation columns, reference gases, or reagents, and runs virtually maintenance-free.

Traditionally, thermal conductivity based analyzers, or Katharometers, have been used to make these sorts of measurements. These analyzers operate by comparing the thermal conductivity of the measured gas to that of a reference gas. The BGA244 offers dramatic improvement in performance over thermal conductivity based gas analyzers.

- Ten times better accuracy
- Thousand times better stability
- Tremendous flexibility with nearly 500 pre-calibrated gases

In addition, the BGA244 can lower the cost of ownership. Most applications don’t require any zero or span gas calibration, reducing both installation and maintenance costs. See (Tech note – Comparing Thermal Conductivity Analyzers with the BGA244) for more details on the advantages of the BGA244.

Principle of Operation

The speed of sound in a gas depends on the temperature, specific heat, and the molar mass of the gas. By precisely measuring the speed of sound and temperature in a gas mixture, and knowing the thermodynamic properties and molar masses of the gases, the BGA244 determines the composition of gas mixtures with an accuracy of about 0.1 %.

Operating Modes

The BGA244 has three basic measurement modes: Binary Gas Analyzer, Gas Purity Analyzer, and Physical Measurements Analyzer.

In Binary Gas Analyzer mode, the ratio of two gases is reported. In Gas Purity Analyzer mode, the purity of a single gas is reported. In Physical Measurements mode, the BGA244 reports the speed of sound, temperature, and gas pressure. This extends the BGA244’s utility beyond gas analysis, for example, to enable the measurement of thermodynamic properties of gas mixtures.

Gases can be chosen by name, formula, or CAS number on the touchscreen display or over the computer interfaces. In each mode, the BGA244 displays large numeric readouts of the parameters being measured. In the Binary Gas Analyzer and Gas Purity Analyzer modes, a needle graph shows the user-defined operating range in green, and higher and lower limits in red.

Limits can be set in all modes of operation. High and low limits can be defined for gas composition, gas purity, speed of sound, temperature, and pressure. Limits can generate “events”, setting or clearing relays.

Comprehensive Database

Thermodynamic and molar mass data for nearly 500 gases have been tabulated in the BGA244, enabling the instrument to measure tens of thousands of mixtures. Gases can be added to the data tables, as can pseudo-gases (user-defined gas mixtures which are treated as one gas species).

Remarkable Accuracy

The accuracy of the gas composition result depends on the difference in the speed of sound between the gas species.  Shown below are the typical composition errors for several gases mixtures.

For measurements requiring greater accuracy, a REL to the dominant gas species can be performed to remove most of the systematic errors. With this, an accuracy of 10 ppm is possible (depending on the gas species). Contact SRS for information on your specific gas mixture.

                           Gases Composition Error Range
                              Hydrogen/Helium         0.04 % to 0.14 %
                              Helium-3/Helium-4         0.11 % to 0.14 %
                              Helium/Deuterium         0.13 % to 0.29 %
                              Hydrogen/Argon         0.002 % to 0.049 %
                              Helium/Air         0.005 % to 0.035 %
                              Hydrogen/Oxygen         0.002 % to 0.035 %
                              Oxygen/Ozone         0.053 % to 0.11 %
                              Oxygen/Nitrogen         0.24 % to 0.26 %
                              Nitrogen/Carbon Dioxide         0.051 % to 0.12 %
                              Diborane/Hydrogen         0.003 % to 0.086 %
                              Sulfur Hexafluoride/Air         0.007 % to 0.155 %
                              TMI/Hydrogen         0.001 % to 0.002 %
                              TMI/Nitrogen         0.006 % to 0.008 %

Operating Pressure

The accuracy of the BGA244 depends on knowing the operating pressure. In many cases, the pressure is stable and can be entered on the front panel or over the computer interfaces. For applications that have varying operating pressures, an external pressure gauge can be easily connected to one of the analog inputs.The BG244 operates over a pressure range that extends from a few psi up to 150 psi.

Heaters, Relays, I/Os & Power

The BGA244 comes equiped with several multipurpose analog I/Os, two user-defined event relays for process control or alarms, and cavity heaters for temperature regulation and condensation prevention. There is an input for an external 24 VDC power supply. Many customers will choose to order the optional BGA-24 power supply which can supply +24 VDC to the BGA244.


With the standard RS-232, RS-422 and USB computer interfaces, all instrument functions can be set and queried remotely. The instrument can operate independently or via a host computer. A Windows monitor program, BGAMon, records and displays time records of gas composition, temperature, and pressure. The program also can be used to remotely configure the instrument, copy configurations to multiple instruments, and add user gas information.

Models BGA244, BGA244HP & BGA244E

The standard BGA244 comes with 1/8"-27 female NPT gas connectors. A wide variety of stainless steel gas fitting adapters are available for interfacing with NPT, VCR, VCO, tube compression, and flexible hose fittings.

The model BGA244HP High Purity Process Gas Analyzer is designed for use in high purity or corrosive environments. This model comes with welded-in-place1/4" male VCR fittings. The The BGA244HP is helium leak checked.

The model BGA244E gas analyzer is a standard BGA244 analyzer installed inside of an IP66/NEMA-4X rated, impact, UV and corrosion resistant polycarbonate enclosure.  A clear, hinged door allows viewing of the BGA244 display and quick access to the instrument. The sealed enclosure protects the BGA244 from dust, weather and hose directed water. Liquid tight gas ports and flexible non-metallic cable conduit ports are located on the bottom edge of the wall mounted enclosure. The gas ports are 1/8”-27 female NPT stainless steel fittings. Electrical connections are made through 3/4” FNMC-B conduit fittings.

Model BGA244OEM

The BGA244 can be ordered in several OEM configurations and is priced accordingly. Please call us to discuss your application.

The BGA244 can be used in a very diverse range of applications.

MOCVD gases
Heat treating and welding gas monitoring
Helium & Hydrogen purity measurements
Gas blending
Argon purity
Ozone generation
Industrial gas processes
Ammonia synthesis
Hydrogen and chlorine for chlorine production
Hydrogen and oxygen purity in electrolysis
Purge gas monitoring
Blanketing gas monitoring
Glove boxes
Inerting gases
Food processing gas monitoring
Food packaging gases









Phone: (408)744-9040 • Fax: (408)744-9049 • email:

BGA244 Binary Gas Analyzer
Operating temperature -20 °C to +70 °C
Temperature resolution 0.001 °C
Temperature accuracy ±0.1 °C
Speed of sound range 100 to 1500 m/s
Speed of sound resolution 0.001 m/s
Speed of sound accuracy ±0.05 % (1 atm argon at 200 sccm)
Concentration accuracy ±0.1 % typ. (species dependent)
Measurement rate 4.4 Hz
Exponential averaging Off, or 2 to 100 periods
Volume 130 cc
Operating flow rate 0 to 5000 sccm
Minimum operating pressure (psi) <5 psia typ. (species dependent)
Cavity proof pressure 2,500 psi
In-bound helium leak rate 1 × 10–8 std-cc/s (BGA244HP only)
Analog I/O
Ports 3 output ports, 2 input ports
I/O port ranges 0 to 5 V, 0 to 10 V, and 4 to 20 mA
Accuracy Voltage: ±0.1 % + 1 mV, Current: ±0.1 % + 10 µA
4-20 mA loop power 6 to 19 VDC
4-20 mA output compliance 0 to 16.8 VDC
Cavity Heaters
Set temperature 0 °C to 70 °C
Power limit Off, or 0.5 W to 60 W
Serial Communication
USB WHQL high speed USB 2.0
RS-232 2400 to 115,200 baud
RS-422 2400 to 115,200 baud
USB power +5 V, 350 mA (when not using +24 V)
+24 V Current 0.1 A to 2.5 A depending on heater power
Wetted materials Electropolished 304 stainless steel, OFHC copper gaskets (gold flashed, BGA244HP only), nickel plated/Immersion gold copper traces on 0.001" Kapton film, glass, Dumet wire, and vented 316 stainless steel screws. Loctite 565 thread sealant used on gas fittings for BGA244 and BGA244E.
Gas fittings BGA244 and BGA244E: 1/8"-27 female NPT
BGA244HP: Welded 1/4" male VCR
Dimensions BGA244 and BGA244HP: 5" × 4.5" × 3.25" (WHD)
BGA244E: 10" ×11" × 5.5" (WHL)
Weight BGA244 and BGA244HP: 7 lbs.
BGA244E: 10.2 lbs.
Warranty One year parts and labor on defects in materials & workmanship
*** Important Safety Note

The BGA244 is not ATEX rated. Under normal operating conditions the BGA244 cannot ignite the gas being analyzed. However, if the instrument is used with flammable or explosive gas mixtures we recommend the use of flame arrestors on both gas ports.

The instrument’s proof pressure (2,500 psia) is sufficient to contain the denotation of an explosive gas mixture of up to 30 psia. The instrument would not operate after such an event.

The instrument’s acoustic transducer consists of a nickel-plated copper spiral on a 40 μm thick Kapton polyimide film. For gases that may react with copper or Kapton, we recommend corrosion testing of this component on a case-by-case basis.

Phone: (408)744-9040 • Fax: (408)744-9049 • email:

BGAMon Software

BGAMon is a Windows based data acquisition and control program for the BGA244. It can be used to display and configure all instrument parameters, save and recall instrument configurations, acquire data, and add gases to the gas table.

Real Time Monitoring

BGAMon can monitor measurement data as well as instrument settings in real time. Any changes made on the BGA244 front panel or in BGAMon are immediateley reflected to the other.

Loading and Saving Configurations

Entire BGA244 configurations can be saved and recalled from your computer. This can be useful when configuring multiple instruments.

Data Logging

The BGAMon Strip Chart feature can acquire, plot, print and export measurements from the BGA244. The following measurements can be captured and then printed or exported to a file.

Primary and secondary gas concentrations

Gas purity

Measured speed of sound and speed of sound normalized to NTP (normal temperature and pressure)

Gas temperature

Heater power

Pressure (User, Pressure Gauge 1 & 2, Analysis Pressure)

Analog inputs (input 1 and 2, voltage or current)

Data is acquired at the 4.4 Hz measurement rate giving fast, real time performance. Data can be displayed over time intervals ranging from seconds to hundreds of days to monitor both short term transients and long term trends.

Gas Selection

You can search nearly 500 different gases contained in the BGA244's gas library. The gases are displayed in a spreadsheet that can be sorted by CAS number, name, formula, mass, heat capacity, or speed of sound. A search function allows the table to be searched by CAS number, name or formula.

User specified gases can be added to or removed from the BGA244's gas table using BGAMon.


BGAMon runs on the following Microsoft Windows operating systems: XP, Vista, Win 7, Win 8 and Win 10. Your computer must have  a high speed USB 2.0 port..







Phone: (408)744-9040 • Fax: (408)744-9049 • email: