In fire incidents, smoke is more dangerous to human beings than fire itself. The smoke can also result in reduced visibility, toxic gas emissions, and the inability to evacuate or rescue people due to disorientation. Consequently, the determination of smoke production properties has come to be an essential element of material fire safety tests. This kind of testing can help the engineers and regulators to determine whether materials are safe to be used in an enclosed environment or high occupancy environment, where the accumulation of smoke can have dire consequences.
Purpose of Smoke Density Measurement
The main task of smoke density measurement is to determine the extent of smoke a material generates under heat or flame. The test is used to understand that a material causes a loss of visibility when there is a fire, and to check its appropriateness in safety-critical use. The outcomes are employed to categorize materials by the level of smoke production and ensure that fire safety measures and building codes are met.
Common Smoke Density Test Methods
The NBS Smoke Chamber test, standardized in ASTM E662, is amongst the most popular techniques of measuring smoke density. It is an optical density technique that is used to determine the density of smoke emitted by a substance during flaming and non-flaming conditions. Other associated techniques can be used in cases of industries, like transportation and aerospace, in which other factors like toxicity and heat release are also considered.
Test Procedure Overview
In smoke density testing, a sealed test chamber is used, whereby the specimen is subjected to a controlled heat source or flame. The decomposing or burning material causes smoke to be produced in the chamber. A photometric system is used to measure the light that is lost by smoke. The optical density of smoke can be measured as time goes by, which enables defining the maximum smoke density and smoke development pattern in the given conditions.
