The global energy demand is on the rise while the need for decarbonization is becoming increasingly urgent. Green hydrogen, produced through electrolysis using renewable electricity, is emerging as a promising solution to reduce emissions in energy generation. Despite the environmental benefits of hydrogen as a clean-burning fuel, traditional methods of large-scale hydrogen production often rely on fossil fuels, leading to 'grey' or 'blue' hydrogen with significant carbon footprints. The shift towards 'green hydrogen' offers a cleaner alternative by leveraging renewable energy sources. The article explores the challenges and advancements in green hydrogen production. It discusses the importance of precise process control for safety and efficiency, as well as the different types of electrolysis technologies available. Alkaline electrolyte cells, polymer electrolyte membranes, and solid oxide electrolysers each have their unique characteristics impacting cost, efficiency, and operational temperatures. Measurement instruments are essential for monitoring and optimizing the electrolysis process. The use of smart measurement devices enables continuous monitoring of various parameters, ensuring early detection of anomalies and potential faults. Gas analyzers are crucial in detecting safety risks such as oxygen build-up in the hydrogen stream, while liquid level measurement instruments help in monitoring separation processes within the electrolyser. Temperature control is highlighted as a key aspect to prevent overheating in electrolysis. ABB's gas analyser, EasyLine EL3060, is specifically designed for hazardous environments, offering precise hydrogen measurement and safety features. Magnetic level instruments are recommended for liquid level measurement in the electrolysis process due to their non-contact nature and ease of maintenance. Overall, innovative measurement technologies play a vital role in driving the green hydrogen revolution by enhancing safety, efficiency, and environmental impact in hydrogen production.