FTT Single Burning Item (SBI)
The Importance of the SBI
The European Construction Products Regulation requires that all European Member states use this test method to evaluate reaction to fire performance for all construction products excluding flooring. These test methods will eventually take precedence over national regulatory methods to classify most building products and will be required by all suppliers of building materials into the EU and neighbouring states adopting these regulations.
The SBI Test
The Single Burning Item (SBI), is a method of test for determining the reaction to fire behavior of building products (excluding floorings) when exposed to the thermal attack from a single burning item (modeled by a propane fuelled sandbox burner). The specimen is mounted on a trolley that is positioned in a frame beneath an exhaust system. The reaction of the specimen to the burner is monitored instrumentally and visually. Heat and smoke release rates are calculated and physical characteristics are assessed by observation. The parameters that are quantified in this test and used within the classification criteria are Total Heat Release (THR), Fire Growth Rate Index (FIGRA) and Smoke Growth Rate index (SMOGRA).
How the SBI is used to classify products
The European Commission recently defined the classification criteria for building products. These performance classes range from A to F. Although other test methods are required for assessment, SBI testing is needed to classify all non flooring products qualifying for classes A2, B, C and D, which are the major classes inhabited by most products other than those that are principally inorganic and classified as noncombustible (A1).
The FTT SBI
FTT supplies and installs the apparatus and train clients in its use. FTT can also supply any of the components to clients wishing to part design and build their own equipment.
The main components of the FTT SBI are:
- Frame, trolley, hood and ducting.
- Gas analysis instrumentation for heat release measurement.
- Smoke measurement system.
- Burner, gas train and controls.
- Data acquisition and analysis software.
Test apparatus includes:
- Trolley, which holds the specimen and which docks into the frame.
- Primary and secondary burners.
- Frame, which is built into the test room.
- Collector with baffles, fitted to the hood.
- Ducting with guide vanes.
- Duct section containing gas sampling probe, bidirectional probe and thermocouples for mass flow measurement and smoke measuring ports.
Gas Analysis Instrumentation
Housed in a 19″ rack containing:
- Oxygen Analyser (paramagnetic) supplied with temperature and pressure compensation. Used for primary heat release measurement.
- Carbon Dioxide Analyser (infrared) for use in heat release measurement.
- Soot filter, refrigerant cold trap, drying column(s), pump and waste regulators for conditioning the sampled gases prior to analysis.
- Controls for the smoke measurement system (if purchased).
- Data Logger (if purchased).
Clients owning an FTT Dual Cone Calorimeter can use the instrument rack from the cone for this function. Similarly clients purchasing this equipment will own a substantial section of a FTT Dual Cone Calorimeter and later be able to purchase a Cone Calorimeter with significant savings.
Smoke Measurement System
- White light source and lens built in accordance with DIN 50055.
- Silicon photodiode detector and voltage output of transmission
- SBI support cradle
- Full set of calibration filters.
- Analysis is via software.
Burner, Gas Train and Controls
- Two non-aerated sandbox burners and an ignition system.
- UV burner flame detector units for safe gas supply monitoring.
- ‘Gas Control Box’, housed next to the test room observation window so the operator can simultaneously see the test specimen and digital propane mass flow rate (mg/s). This unit includes three flow level controllers, warning lights and override facilities.
- ‘Gas Diverter’ consisting of a mass flow controller to control the propane gas flow. Solenoid valves and flash back arrestors in both gas supply lines for automated safe operation of the gas flow to the burners. These are housed close to the test frame to improve the response time of the burners by reducing the pipe length between the solenoids and burners. The propane mass flow rate and the corresponding heat release (kW) are additionally displayed via software.
Data acquisition and analysis
- A Windows based software package enabling simple data collection and manipulation to determine the various parameters needed for heat release determination. The software generates files that integrate with the current spreadsheets, (which are also supplied) for the calculation of the Fire Growth Rate Index (FIGRA) and Smoke Growth Rate Index (SMOGRA).
- Data logger, which features a 3slot card cage with 6 1/2 digit (22 bit) internal DMM enabling up to 120 single ended or 48 double ended measurements, collects signals from the instrumentation. Scan rates up to 250 channel/s are available with a 115 kbaud RS232 interface as standard. Also supplied with GPIB interface.