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Temperature Oxygen Index Apparatus

ISO 4589-3; NES 715

The FTT Oxygen Index (OI) and Temperature Oxygen Index (TOI), which replace the Stanton Redcroft FTA and HFTA, offer many improvements.

The latest oxygen analyser technology for high accuracy, reliability and long operating life.

Determination of Flammability by Oxygen Index
Oxygen Index is, perhaps, the most economical and precise quality control test of combustible materials. Its ease of use, together with high levels of precision has made this technique a primary characterising and quality control tool to the plastic and electric cable industries and it has been specified by several military and transport groups. The technique measures the minimum percentage of oxygen in the test atmosphere which is required to marginally support combustion.

The Temperature Oxygen Index module (TOI) must be used with either the new FTT Oxygen Index apparatus or with any traditional design, to determine the oxygen index at temperatures up to 125°C. Research shows that the elevated temperature at which the materials will burn in air is a better determinant of combustibility than is the conventional oxygen index. Oxygen Index values fall when the gas temperatures are increased. The FTT apparatus enables temperature oxygen index to be determined in accordance with ISO 4589 Part 3 or the UK Naval Engineering Standard NES 715. Elevated test temperatures are set by adjustment of the pre-heated gas temperature levels and setting the heated glass furnace wall temperatures. The temperatures of both heated sections are continuously displayed on the Temperature Index control unit. When experiments are being carried out using different oxygen levels, gas conservation is achieved by using air from an integral quiet running pump between tests. Bottled nitrogen and oxygen supplies are only switched into the system for testing.

The FTT unit has been designed to be compact for efficient use in a standard fume cupboard (or under a simple ventilation hood that we can also supply if required). The Oxygen Index unit gives a continuous digital readout of oxygen concentrations in the test atmosphere to facilitate quick settings of test concentration. 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 levels. This makes the unit as automatic as is feasible.


  • Test temperature to 400°C
  • Digital display of sample temperature
  • Digital display of column and pre-heater temperatures
  • Transparent radiant heated test column
  • Highly efficient gas pre-heater
  • Air pump to conserve oxygen and nitrogen supply during standby period


  • Digital readout for oxygen concentration: +/-0.1%
  • Dimensions (mm): 350 (W) × 370 (D) × 280 (H)
  • Column size (mm): 160 max (dia.) × 75mm (internal dia.) × 570 (H)
  • Weight: 17 kg
  • Voltage: 230V 50Hz 10.25A or 110V 60Hz 20.5A
  • Operating Manual: Supplied
  • Other Service requirements: Bottled O2/N2, Propane, Requires Oxygen Index
Temperature Oxygen Index Apparatus

Temperature Oxygen Index Apparatus

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