Read-Ox has developed a hydrogen sensor for in-line measurement of the partial hydrogen pressure in molten tin or the surrounding atmosphere. The sensor is built around an indium-doped CaZrO₃ solid electrolyte cell (4a) and continuously monitors the hydrogen activity in the tin melt or the %H₂ concentration in the atmosphere at temperatures up to 900°C. For accurate operation, the internal chamber of the CaZrO₃ cell must be flushed with a reference gas (via gas inlet 1a) containing a defined hydrogen concentration, typically 1% H₂ in N₂.

High hydrogen levels in the hot-end section of the tin bath can lead to the formation of hydrogen gas bubbles in the molten tin, potentially damaging the bottom surface of the glass ribbon. Additionally, partial or full oxy-fuel firing in the upstream glass melting sections may contribute to this issue. Oxy-fuel combustion increases the water vapor content in the atmosphere, which in turn raises the water content of the glass melt. Under the reducing conditions of the tin bath, water can diffuse from the glass ribbon into the tin and dissociate into H₂ and O₂ gases, further elevating hydrogen levels. This can result in the formation of hydrogen bubbles beneath the ribbon, compromising product quality and process stability.