NUNES Oxygen Index Apparatus consists of a test chimney made of borosilicate glass suppurated by the metallic base and hook with the help of the metallic pillar. The mixture of nitrogen and oxygen is released from the bottom of tube. The tube is filled with glass beads for mixing and evenly distributing the gas mixture. The specimen holder, which holds the test specimen, made of U shape and fixed at the center of the chimney. There is the porous screen mounted below the level of the specimen holder, to prevent falling combustion debris from fouling the gas entry and distribution paths. There is a digital temperature indicator cum controller with thermocouple for the measurement. A copper tube with suitable orifice for pilot flame is provided for igniting the specimen by inserting it from the top of the test column. The digital preset timer and buzzer is also mount in the instrument. Two rotameter with needle valve are provided to control and measure oxygen and nitrogen flow in the test chimney. A timer for indicating the time of burning with a reset switch. The rotameter, temperature controller, timer are fitted in the sheet panel. The test chimney is fitted separately on the metallic platform. Gases, gas cylinders and its fittings are not provided with the equipment and have to be arranged by the purchaser.