Gas Chromotography TCD Hydrogen Calibration Valve

An in-line valve designed specifically to direct the flow of gasses within a gas chromotography machine.

The Need

Current metallurgy research requires a hydrogen measurement device to quantify the amount of hydrogen in a weld and the diffusion rate of hydrogen after failure to analyze the effects hydrogen assisted cracking. With this information, research groups can evaluate the performance of various welds and engineer new methods to prevent hydrogen assisted cracking. Companies are interested in a solution to hydrogen assisted cracking to prevent large gas pipelines from fracturing and leaking into the environment and other similar applications. Only a few hydrogen measurement devices are commercially produced and are sold by large companies with set capabilities at a high price.

The Technology

Researchers at The Ohio State University, led by Dr. Boian Alexandrov, have designed a physical valve that directs the flow of gasses within a gas chromatography (GC) TCD machine. The device works with an existing GC TCD to test small metal and welded samples for hydrogen content and hydrogen diffusion rates to assist the research of hydrogen cracking in welds. The valve grants both gas calibration and flow control to a GC TCD system in a single compact design. The current design is built to calibrate the system with small volumes of hydrogen ranging from 5 to 100 mm3 with high precision. This is only applicable for testing and measuring hydrogen in small samples within these set ranges, but the valve can be easily redesigned to fit both smaller and larger applications by adjusting the depth of the volume disk channels.

Commercial Application

  • Gas calibration and flowrate control for a GC TCD system
  • Evaluate metal and welded samples for hydrogen content and diffusion rate to limit hydrogen assisted cracking


  • Compact design for easy, in-the-field use

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