NBS Smoke Chamber

(ASTM E662; BS 6401; NFPA 258)
And options for:
(ISO 5659; ABD0031 (ATS 1000.001); NES 711)

The NBS Smoke Density Chamber is widely used in all industrial sectors for the determination of smoke generated by solid materials and assemblies mounted in the vertical orientation within a closed chamber. It measures the specific optical density of smoke generated by materials when an essentially flat specimen, up to 25 mm thick, is exposed to a radiant heat source of25kW/m2, in a closed chamber, with or without the use of a pilot flame. The radiant heat source can be easily replaced with the Conical Radiant Furnace for testing of specimens in the horizontal orientation according to ISO 5659 and IMO FTP Part 2 requirements.

Features of the FTT NBS
Smoke Density
Chamber (SDC)

  • Test chamber with full width opening door, easy access for sample loading & cleaning.
  • Photomultiplier control unit with manual zero and span controls to be used with the FTT software to perform automatic control of the test procedure on the SDC
  • Controls are mounted beside the chamber for convenient operation.
  • Three term temperature controller for radiant heat source with digital display.
  • Chamber walls are preheated for easier startup and convenient equipment operation.
  • Safety blowout panel, easily replaceable, allows for safe operation of test method.
  • Gas measurement ports are available, for optional measurements of toxic gases.
  • Cabinet designed with a standard 19″ rack, for simple addition of gas analysers, chart recorder and other control units.
  • Air cooled radiometer for furnace flux calibration.

The FTT SDC was designed to incorporate the ISO 5659 Conical Radiant Furnace. This extends the potential of the SDC by allowing testing at heat fluxes up to 50 kW/m2, horizontal orientation of the specimen and the measurement of mass loss rate of the specimen. It takes 15 minutes to change from ASTM E662 to the ISO 5659 configuration, which conforms to the recent IMO test protocols.


The FTT SDC is supplied with a software package called SmokeBox, which was designed as a data acquisition and presentation package allowing either manual or automatic control. This enables a more efficient use of the instrument, leading to larger daily throughput of testing and enhanced quality graphical data presentation. ‘SmokeBox’ is a Microsoft Windows based package which collects test data and assists with all calibration routines. It can be used for several applications such as: standardized testing to ASTM E662, ISO 5659 and BS 6401etc.

SmokeBox enables:

  • Calibration of the photomultiplier amplifier
  • Automatic file naming

Data collection:

The start of an experiment is initiated by the activation of a footswitch or the push of a button on the computer screen. Information about the test and the sample is entered prior to the run. This is stored to disk, together with the numerical data generated during the test. Data is collected and stored at user defined intervals. The intervals can be defined over a range from 1 to 60 seconds. Real time data is displayed on the VDU during the course of a test. The information is displayed in graphical and textual form. The graphical form is an autoscaling graph with time on the x-axis and transmission (%) and specific optical density on two y-axes.

Textual data includes:

  • Instantaneous transmission (%) & specific optical density (DS)
  • Time from start of test
  • Maximum DS and time to maximum DS
  • Current range setting and filter position
  • Mass (ISO 5659)
  • Prompts (visual and audio) when the range setting or filter position requires changing when operating in manual mode.When operating under software control the range setting is automatically changed.

The experimental data stored during a run includes:

  • Tim (sec), t
  • Transmission (%) at time t
  • Specific optical density at time t
  • Range and filter positions at time t
  • Mass (g) at time t (ISO 5659)

On completion of the test, the clear beam transmission is recorded to correct the data for deposits on the optical system. A report including a graph and table of specific optical density (DS) against time is produced. The report can be printed on any device with a Windows driver.

We are the only authorized Fire Testing Technology Agent in North America.