The Critical Oxygen Index Tester is perhaps the most economical and precise quality control test for combustible materials. Its ease of use together with high levels of precision has made this technique a primary characterization and quality control tool for the plastic materials and electric cable industries. The instrument provides a precise method for determining the critical oxygen index of the sample by measuring the minimum volume concentration of oxygen in a flowing stream of oxygen and nitrogen required to maintain candle like burning of that sample.
This method enables the relative flammability of materials to be put on a reproducible basis. The unit has been designed to be compact for efficient use in a standard fume cupboard. Stabilised oxygen percentages are read from the digital readout and no additional flow adjustments are required. This is a considerable improvement over systems that use analogue gauges or require flow matching and the use of graphs or tables to calculate oxygen concentrations. This makes the unit as automatic as is feasible.