The complete solution Set GGA

Turbo generators in power plants are cooled with gas in order to increase their efficiency. In spite of the strict safety requirements hydrogen is used as a cooling gas. This offers huge advantages over air. These include considerably better cooling properties, lower friction loss on rotating parts, and a higher electrical breakdown strength. These features enable hydrogen to satisfy the requirements for the turbo generator to reach an optimum level of efficiency. The Set GGA (Generator Gas Analyzer) is a standardized set to control hydrogen-cooled turbo generators.

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The complete solution for hydrogen-cooled turbo generators

Set GGA – Continuous monitoring

Hydrogen gas is potentially explosive in mixtures with air over a wide concentration range (4 to 77%). Formation of such mixtures must be prevented for safety reasons during normal operation as well as during maintenance work. International Standards (EN and IEC) specify the installation of a redundant safety control system with two independent measuring systems.


In addition, contamination of the hydrogen cooling gas reduces the efficiency of the turbo generator, as it leads to considerably higher friction loss. For a 970 MW generator, a difference of 4% is equivalent to a 0.8 MW difference in power. There are also good reasons related to cost-effectiveness why the cooling gas should be continuously monitored for contamination.


The Set GGA is a complete solution for monitoring hydrogen-cooled turbo generators, with the dual benefit of being simple to handle and having low initial investment costs.


The CALOMAT 6 Analyzer System provides complete solution to control hydrogen-cooled turbine generators. 

The system complies with all relevant international directives by using two entirely independent (from gas sampling at the generator to gas outlet at the analyzer) gas analyzer lines in one rack. The gas analyzer CALOMAT 6 used in the system is designed for continuous determination of primarily H2 and He in binary or quasi-binary gas mixtures. The measuring principle is based on the different thermal conductivity of gases. 

Benefits at a glance

Standardized complete system

  • Simple and fast to configure
  • Field-proven, harmonized and reliable set
  • Low purchase price and economic operation
  • Suitable for optimizing the efficiency of H2-cooled turbo generators

Field-proven, reliable technologies

  • High-precision and reliable purity monitoring of hydrogen
  • Microchip-based thermal conductivity measurement
  • Redundant measuring system
  •  SIL 1 certificate for the analysis hardware

Simple operation

  • Intuitive menu prompting
  • Configuration on large displays with plaintext
  • Use of CO2 and AR as inert gas possible
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Safety is key in the process industries. A failure in instruments relevant for safety may have serious implications for humans, the process and the environment. Therefore, a wide range of our process instruments come with on-board safety features for maximum risk reduction.


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