Hazardous gas in the confined space is an issue that often causes danger to the worker while doing the tasks i.e. installation, cleaning and maintenance. The nature of the area may exposure the worker to hazardous gas leakage. It is important to monitor the hazardous gas in the surrounding area before the worker start their task inside the confined space. This paper proposes a study of developing a web-based mobile olfaction system for confined space hazardous gas monitoring. The system is integration between a mobile robot and an electronic nose (e-nose). The system will reduce the danger faced by the worker from the hazardous gas. The e-nose consists of a sensor array, embedded controller, electronic components and wireless GSM communication. The instrument sensors i.e. hydrogen sulphide, oxygen, carbon monoxide and methane are used to acquire the confined space air sample. It will also acquire the environment temperature and humidity. The robot which piggyback the instrument will manoeuvre through the environment while acquires data. The data acquired were transmitted and monitored wirelessly to the web-based information system. The website layout is designed using HTML and JavaScript. Data received from e-nose will be stored into a database, MySQL server before being process by the website. The data will go through the conversion process from digital value to PPM. Then the data will be classified using ANN to obtain the Hazardous Gas Concentration Index (HGCI). The website will display the HGCI mapping of the area in real-time. Results show that the system performance is good and can be used to monitor the hazardous gas in the confined space.
