Smoke Density Chamber ISO 5659-2, ASTM E662

Smoke Density Chamber (ISO 5659-2)

The Smoke Density Chamber, standardized in ISO 5659-2, is one of the most widely applied test instruments for evaluating the smoke generation characteristics of materials. It is applicable to plastics, building products, non-metallic materials in railway vehicles, marine applications, and aircraft interiors, among others.

This method provides a means of measuring optical smoke density under controlled laboratory conditions. However, it is not intended for use as a direct predictor of smoke behaviour under actual fire exposure scenarios, nor as a basis for regulatory building code ratings. Instead, it is primarily used in research, development, and fire safety engineering to characterize material performance.

Limitations of the Method

The test results represent material behaviour under the specific exposure conditions of the chamber and may not be representative of full-scale fire conditions.
ISO 5659-2 does not establish a direct correlation for predicting toxic hazard or the actual smoke density in real fires.
The method is thus best suited for comparative testing and quality control rather than life-safety design predictions.

Parameters Reported in ISO 5659-2 Testing

The following parameters may be determined and reported:

Specific Optical Density (Ds):
- Maximum specific optical density (Dsmax)
- Time-dependent values such as Ds(1.5), Ds(4.0), Ds(10)
Clear-beam correction factor (Dc)
VOF4 (Value of Optical Density at 4 min): A parameter used to characterize early smoke development
Results from other referenced or harmonized standards, where applicable

Yes I'm Interested

Smoke Density Chamber (ISO 5659-2 & EN 17084 Compliant)

The Smoke Density Chamber is constructed of thick stainless steel with an internal volume of 914 mm × 914 mm × 610 mm. The inner surfaces are coated with Teflon® (PTFE) to ensure resistance to chemical attack and corrosion and to facilitate easy cleaning.

A full-opening front door allows convenient sample loading and chamber maintenance. The door is equipped with an observation window and a removable opaque cover, preventing stray light from entering during the test. The chamber walls can be pre-heated to stabilize test conditions and reduce start-up times.

To ensure operator safety, the chamber incorporates a pressure-relief device designed to mitigate the risk of explosion and allow for safe operation.

Optical System

Two optical windows, each with a 75 mm diameter, are mounted on the top and bottom of the chamber.
The light transmission system consists of an incandescent lamp (source) and a photomultiplier tube (detector).
A range-extension filter in the light path allows accurate measurement over the full scale of smoke density.

Heating and Ignition System

ISO 5659-2 Conical Radiant Heater: 2600 W at 230 V, capable of producing irradiance up to 50 kW/m² at the specimen surface.
ASTM E662 Vertical Furnace Heater: 550 W at 110 V, providing irradiance up to 25 kW/m².
Automatic split shutter controls specimen exposure to the radiant flux.
Pilot flame ignition system with selectable flaming and non-flaming test modes.
Heat flux meter provided for accurate calibration of the irradiance range 0–100 kW/m².

Sample Handling & Gas Supply

Specimen movement and positioning are air-cylinder actuated and automatically controlled.
Air and propane flows for the pilot system are digitally displayed and controlled.
Gas sampling ports are integrated into the chamber to allow optional measurement of combustion gases.

Control & Data Acquisition

Integrated 19″ analysis rack with 15″ touch-screen panel PC for chamber control, test parameter input, and result acquisition.
DAQ software system ensures automated test execution, real-time data logging, and compliance with reporting requirements.

Advanced Options (EN 17084)

Provision for connection to FTIR Gas Analysis System for quantitative measurement of toxic gases (e.g., CO, CO?, HCN, HCl, HF, SO?, NO?) as specified in EN 17084.
Enables combined evaluation of smoke optical density and toxic gas concentrations under the same exposure conditions.

Specification: Smoke Density Chamber (ISO 5659-2 / EN 17084 Compliant)

1. General Construction

1.1 The chamber shall be manufactured from thick stainless steel, with an internal size of 914 mm × 914 mm × 610 mm.
1.2 The inner surfaces shall be coated with Teflon® (PTFE) to ensure resistance to chemical attack, corrosion, and to facilitate easy cleaning.
1.3 The chamber shall be equipped with a full-opening front door to allow convenient specimen loading and internal maintenance.
1.4 The door shall be fitted with an observation window and a removable opaque cover to prevent external light interference during testing.
1.5 The chamber walls shall have provision for pre-heating, ensuring stable operating conditions and reduced start-up time.
1.6 A safety relief device shall be provided to prevent explosion and enable safe operation of the test.

2. Optical System

2.1 The chamber shall be fitted with two optical windows, each of 75 mm diameter, located at the top and bottom of the chamber.
2.2 The light source shall consist of an incandescent lamp.
2.3 The light detection system shall employ a photomultiplier tube, with sensitivity suitable for smoke optical density measurement.
2.4 A range-extension filter shall be included in the optical path to maintain accuracy across the full scale of measurement.
2.5 The system shall allow determination of Specific Optical Density (Ds) as required by ISO 5659-2, including Dsmax, Ds1.5, Ds4.0, Ds10, and VOF4.

3. Heating and Ignition System

3.1 The chamber shall include a conical radiant heater in accordance with ISO 5659-2, rated 2600 W at 230 V, capable of delivering irradiance up to 50 kW/m².
3.2 The chamber shall also include a vertical furnace heater in accordance with ASTM E662, rated 550 W at 110 V, with maximum output of 25 kW/m².
3.3 A heat flux meter shall be supplied for calibration of irradiance levels in the range 0–100 kW/m².
3.4 A motorized split shutter shall be provided to control the start of specimen exposure to the radiant source.
3.5 An automatic pilot ignition system shall be included, with both flaming and non-flaming test modes selectable.
3.6 The air and propane supply for the pilot system shall be digitally displayed and accurately controlled.

4. Specimen Handling

4.1 The movement of specimens into the test position shall be automatically controlled by an air cylinder system.
4.2 The system shall allow precise and repeatable specimen positioning.

5. Gas Sampling and Toxicity (EN 17084)

5.1 The chamber shall be provided with gas sampling ports for optional extraction of combustion gases.
5.2 When required, the chamber shall be connectable to an FTIR Gas Analysis System for toxic gas measurements as per EN 17084.
5.3 The FTIR system shall be capable of quantitative determination of gases including, but not limited to:

Carbon monoxide (CO)
Carbon dioxide (CO?)
Hydrogen cyanide (HCN)
Hydrogen chloride (HCl)
Hydrogen fluoride (HF)
Sulphur dioxide (SO?)
Nitrogen oxides (NO, NO?)

6. Control and Data Acquisition

6.1 The chamber shall be supplied with a 19″ analysis rack integrating all control and analysis modules.
6.2 A 15″ touch-screen panel PC shall provide full test control, parameter setting, and monitoring.
6.3 The system shall be equipped with a Data Acquisition (DAQ) software package, enabling:

Automated test control
Real-time measurement and logging of optical density
Storage and reporting of results in compliance with ISO 5659-2
Optional integration of FTIR gas analysis results (EN 17084)

7. Advanced Options

7.1 An optional FTIR Toxicity Test System shall be available for EN 17084 compliance.
7.2 The advanced system shall provide combined smoke density and toxicity analysis, allowing comprehensive material fire performance evaluation.