Totally pyrographite cuvettes

Pyrolytic graphite is a highly anisotropic material, which means that its physical properties are different in different crystal directions. In a parallel direction to the tube surface the heat conductivity of pyrolytic graphite is about 300 times higher than in the vertical direction to the surface. This means that heating along the tube is rapid, whereas heat conduction outwards is poor. 

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The lifetime of TPCs is much longer than pyrolytically coated or normal graphite tubes. Figure 60 shows peak shapes for vanadium and platinum using totally pyrographite cuvettes, pyrolytically coated cuvettes, and electrographite cuvettes. The TPC peak is narrower and appears earlier than the peaks of the other cuvette types. 

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