Oxygen index is defined as the measure of the percentage of oxygen, expressed as volume percent, in a mixture of oxygen and nitrogen that has to be present to support flaming combustion of the plastic materials under equilibrium conditions.

Oxygen index apparatus is used to determine the oxygen index of plastic materials.

Salient Features

The important features associated with the equipment are:

• The apparatus comprises of a test column made of borosilicate glass and supported on a brass base.
• There is a provision for releasing the mixture of oxygen and nitrogen from the bottom of the tube.
• The tube is filled with glass beads for mixing and distributing the gas mixture evenly.
• The equipment is supplied with a specimen holder to hold the specimen vertically in the middle of the test column. The specimen holder is supported in a glass tube fixed at the center of the test column.
• Provided with two rotameters with needle valves to control and measure oxygen and nitrogen flow in the test column.
• Also supplied with a thermocouple probe in the test column above the surface of the beads in order to measure the temperature of the gases inside the column that is indicated on a digital temperature indicator.

Applications

The oxygen index apparatus is commonly used in following areas:

• Plastic Industry
• Fire Testing
• Research & Development
• Chemical Industry