Binary Gas Analyzer
BGA244 — Gas ratio measurement to 0.1 % accuracy

BGA244 Binary Gas Analyzer· Measures ratio of two gases· Analyzes purity of a single gas· <0.1 % accuracy (typ.)· Touch screen display· Data acquisition software (BGAMon)· 4 Hz measurement rate
· USB, RS-232 and RS-422

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 gasblending, PSA (pressure swing adsorption), helium recovery,
dopants in carrier gases, ozone purity and general researchwhere precise measurements of gas mixtures are necessary.
The BGA244 operates without lasers, filaments, chemicalsensors, optical sources, separation columns, reference gases,or reagents, and runs virtually maintenance-free.
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 andmolar masses of the gases, the BGA244 determines thecomposition 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.

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BGA244 Binary Gas Analyzer

to the data tables, as can pseudo-gases (user-defined gasmixtures which are treated as one gas species).
Remarkable Accuracy
The accuracy of the gas composition result depends on thedifference in the speed of sound between the gas species.
Shown below are the typical composition errors for severalgases mixtures.

Binary Gas Analyzer mode
In Binary Gas Analyzer mode, the ratio of two gases isreported. 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.

For measurements requiring greater accuracy, a REL to thedominant gas species can be performed to remove most of thesystematic 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
Helium-3/Helium-4
Helium/Deuterium
Hydrogen/Argon
Helium/Air
Hydrogen/Oxygen
Oxygen/Ozone
Oxygen/Nitrogen
Nitrogen/Carbon Dioxide
Diborane/Hydrogen
Sulfur Hexafluoride/Air
TMI/Hydrogen
TMI/Nitrogen0.04 % to 0.14 %0.11 % to 0.14 %0.13 % to 0.29 %0.002 % to 0.049 %0.005 % to 0.035 %0.002 % to 0.035 %0.053 % to 0.11 %0.24 % to 0.26 %0.051 % to 0.12 %0.003 % to 0.086 %0.007 % to 0.155 %0.001 % to 0.002 %0.006 % to 0.008 %Operating Pressure

Gas Purity Analyzer mode

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

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 ofthe parameters being measured. In the Binary Gas Analyzer
and Gas Purity Analyzer modes, a needle graph shows theuser-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, speedof sound, temperature, and pressure. Limits can generate“events”, setting or clearing relays.
Comprehensive Database
Thermodynamic and molar mass data for more than 500 gases
have been tabulated in the BGA244, enabling the instrument
to measure tens of thousands of mixtures. Gases can be added

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Physical Measurements Analyzer mode

BGA244 Binary Gas Analyzer

Heaters, Relays, I/Os & Power
The BGA244 comes equipped with several multipurpose
analog I/Os, two user-defined event relays for process control
or alarms, and cavity heaters for temperature regulation andcondensation prevention. There is an input for an external
24 VDC power supply. Many customers will choose toorder the optional BGA-24 power supply which can supply+24 VDC to the BGA244.
Communication
With the standard RS-232, RS-422 and USB computerinterfaces, 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 toremotely configure the instrument, copy configurations tomultiple instruments, and add user gas information.

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 theBGA244 from dust, weather and hose directed water. Liquidtight 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 yourapplication.

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-place 1/4” male VCRfittings. The BGA244HP is helium leak checked.

BGA244OEM

BGA244E

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BGA244 Specifications

Serial Communication

Operation
Operating temperature
Temperature resolution
Temperature accuracy
Speed of sound range
Speed of sound resolution
Speed of sound accuracy
Concentration accuracy
Measurement rate
Exponential averaging–20 °C to +70 °C
0.001 °C
±0.1 °C
100 to 1500 m/s
0.001 m/s
±0.05 % (1 atm argon at 200 sccm)±0.1 % typ. (species dependent)
4.4 Hz
Off, or 2 to 100 periods

USB
RS-232
RS-422

WHQL high speed USB 2.0
2400 to 115,200 baud
2400 to 115,200 baud

GeneralUSB power+24 V Current
Wetted materials

CavityVolume130 ccOperating flow rate
0 to 5000 sccm
Min. operating pressue (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/OPorts
I/O port ranges
Accuracy
4-20 mA loop power
4-20 mA compliance3 output ports, 2 input ports
0 to 5 V, 0 to 10 V, and 4 to 20 mA
Voltage: ±0.1 % + 1 mVCurrent: ±0.1 % + 10 µA
6 to 19 VDC
0 to 16.8 VDC

Cavity Heaters
Set temperaturePower limit

0 °C to 70 °C
Off, or 0.5 W to 60 W

Gas fittings
BGA244
BGA244HP
BGA244E
Dimensions
BGA244/BGA244HP
BGA244E
Weight
BGA244/BGA244HP
BGA244E
Warranty+5 V, 350 mA(when not using +24 V)
0.1 A to 2.5 A depending onheater power
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 steelscrews. Loctite 565 thread sealantused on gas fittings for BGA244
and BGA244E.
1/8”-27 female NPT
Welded 1/4” male VCR
1/8”-27 female NPT
5.5” × 4.5” × 3.25” (WHD)10” × 11” × 5.5” (WHD)
7 lbs.
10.2 lbs.
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 withflammable 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 denotationof 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 a40 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.

Ordering Information
BGA244
BGA244HP
BGA244E
BGA244 rear panel

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Binary gas analyzer
Binary gas analyzer
BGA in environmental enclosure