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Generator Gas Analyzer (GGA)


eone generator gas analyzer hydrogen

E/One's Generator Gas Analyzer (GGA) for hydrogen-cooled generators is a triple-range sensor/analyzer that provides continuous monitoring of gas purity during all phases of generator operation.

GGA uses a proven monitoring principle, thermal conductivity. GGA is an extremely accurate, robust and stable system that eliminates the issues of drift and need for frequent recalibration seen in other thermal conductivity systems.

Available Configurations

GGA systems are available in a range of configurations, from stand-alone sensor/analyzers and retrofit "drop-in" replacement systems, to comprehensive hydrogen control cabinets that monitor gas purity, provide continuous monitoring of case and differential pressures and interact with plant control systems to assure the highest level of generator efficiency.

E/One also offers a portable hydrogen gas analyzer (PGA). The PGA incorporates the same sensor/analyzer and system electronics found in E/One's other gas purity systems. The PGA is specifically intended for use in non-hazardous environments and/or as an emergency backup if a power plant's primary gas purity monitoring system is compromised.

E/One's hydrogen gas monitor is also available as part of the E/One Gas Station, which lets power plants combine several E/One generator monitoring and control systems onto one skid. Download the GGA brochure for installation into an E/One Gas Station.

E/One's Generator Gas Analyzer for Hydrogen-Cooled Generators, available in stand-alone and portable configurations, or as part of a larger moniroting and control system

Available in North America, E/One offers best-in-class thermal conductivity and vibrating element technology with E/One’s GGA and Yokogawa Corporation of America’s (YCA) GD402. The E/One-YCA alliance brings together industry leaders focused on plant-level relationships and a wide range of generator applications. With E/One’s GGA and YCA’s GD402, operators are provided with options in continuous monitoring of gas purity throughout all phases of generator operation.

Generator Gas Analyzer Features and Benefits

  • Increased generator efficiency and safety
  • Microprocessor controlled
  • Flameproof, explosion-proof, and intrinsically safe designs
  • Custom configurations to meet site-specific requirements
  • Suitable for new and retrofit applications

Download the GGA brochure

Generator Gas Analyzer Specifications

Technology Principle Thermal Conductivity
Case Purity 70% to 100% H2 in Air
Purge 0 to 100% H2 in CO2
  0 to 100% Air in CO2
Flow Rate Nominal 500 cc/min
Resolution +/- 0.1%
Accuracy +/- 0.5% F.S. on H2 in Air
  +/- 1.0% F.S. on H2 or Air in CO2
Linearity +/- 1.0% F.S.
Drift <0.2% / month
Power - Input Voltage 115/230 VAC
Input Frequency 50/60 Hz
Output Signal 4-20 mA current output, self-powered
Output, Relays 30V/1.0 A DC, 120V/0.5 A AC
Alarm, NO and NC 125V/0.005 A resistive DC
  Warning, NO and NC
  Trouble, NO and NC
  Normal, NO and NC
Overall Dimensions Based on configuration
Enclosure Dimensions  
System Electronics Enclosure 11" x 12" x 9.25"
Sensor Cell Enclosure 8" x 10" x 6.25"
Display Enclosure 0.5" x 8.5" x 6.25" or panel
Valve Panel (optional) Mounted per requirement
Weight Based on configuration
Temperature 32-149 F (0-65 C), optional
Relative Humidity 0-95%
Area Classification Class 1, Zone 2, Group IIB + H2
Gas Pressure 100 psi maximum
Gas Connections 1/4" female NPT


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