Density of Smoke from the Burning or Decomposition of Plastics

This reaction to fire test method covers a laboratory procedure for measuring and observing the relative amounts of smoke obscuration produced by the burning or decomposition of plastics. It is intended to be used for measuring the smoke producing characteristics of plastics under controlled conditions of combustion or decomposition.
The measurements are made in terms of the loss of light transmission through a collected volume of smoke produced under controlled, standardized conditions.

This test is used by model code organizations in controlling the use of plastic materials in light transmitting applications. It can be used as an alternative to the ASTM E84 smoke measurement because this test method can readily be performed on thermoplastic materials that may drip and fall out of the E84 test apparatus. Other smoke test apparatus, for example, ASTM E1354 Cone Calorimeter, E662 Smoke Density Chamber, etc. are also available from FTT.

FTT ASTM D2843 Exit Sign Test Apparatus

The FTT Exit Sign Test is designed for the measurement and observation of the smoke producing characteristics of plastics under controlled conditions of combustion or decomposition according to ASTM D284310 but not to be used for measuring any other characteristics of the plastic
combustion. The apparatus consists of:

  • Combustion Chamber
  • Specimen Holder
  • Ignition System
  • Photometric System
  • Control Unit (incl. Smoke Meter)

The test specimen is exposed to flame for the duration of the test, and the smoke is substantially trapped in the chamber in which combustion occurs. A 25mm × 25mm x 6mm (1″ × 1″ × 1⁄4″) specimen is placed on a supporting metal screen and burned in the test chamber under active flame conditions using a propane burner operating at a pressure of 276 kPa (40 psi). The 300mm × 300mm × 790mm (12″ × 12″ × 31″) test chamber is instrumented with a light source, photoelectric cell, and meter to measure light absorption horizontally across the 300mm (12”) light beam path. The chamber is closed during the 4 minute test period except for the 25mm (1”) high ventilation openings around the bottom of the chamber.

Measurement is by means of transmitting a beam of light through the smoke generated by the sample under test to a light measuring receiver. Results obtained are in units of light absorption (%). The light absorption data are acquired by a user friendly software tool and are plotted versus time. Two indexes, the maximum smoke produced and the smoke density rating, are used to rate the material. A heat resisting glass door is fitted to allow observation of the test whilst it is in progress.

ExitSign Software

FTT Exit Sign Test Apparatus is a sophisticated instrument and in order to make the calibration and use of the instrument extremely easy, the ExitSign software package is specially designed to complement the instrument.

ExitSign is a Microsoft Windows based application which assists with calibration routines, acquires test data and produces test reports. The Main panel is used to access all the functions available in ExitSign software:

  • Start Test
  • Status
  • Filter Check
  • Print Report
  • Configure
  • About
  • Exit

Density of Smoke from burning or decomposition of plastics
Density of Smoke from burning or decomposition of plastics

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