SUMMARYCone calorimeter analysis was conducted on 18 thermoplastics with different UL-94 vertical burn test (V) ratings. Ratings varied from V-0 to no rating (NR), and the types of thermoplastics included were polycarbonate (PC), acrylonitrile-butadiene-styrene (ABS), PC/ABS blends, high-impact polystyrene (HIPS), polypropylene (PP), and poly(vinyl chloride) (PVC). Our analysis of the cone calorimeter data found that there were correlations between UL-94 V rating and some cone calorimeter measurements (peak heat release rate (HRR) average and HRR at 60 s) and no relationship for other measurements (time to ignition and total heat release). However, no precise correlation was found due to significant differences in flame retardant mechanism and polymer fuel energy values. In this paper, we seek to explain further why a broad quantitative relationship between UL-94 V and cone calorimeter remains elusive, and also to show how the cone calorimeter can be used to understand why a material passes or fails a particular UL-94 V rating.

Description of data columns (channels) in reduced ASCII data files. Channel Name (units) Description of Measurement Time From Ignition (s) NA NA NA Time relative to ignition defined by Event 1 O2Rear (mol/mol) 29 113 88 Rear O2 volume fraction corrected for water (wet) CO2Rear (mol/mol) 29 113 88 Rear CO2 volume fraction corrected for water (wet) CORear (mol/mol) 29 113 88 Rear CO volume fraction corrected for water (wet) THCRear (mol/mol) 29 113 88 Rear Total Hydrocarbons volume fraction corrected for water (wet) SootRear (g/g)

The National Fire Research Laboratory is a unique large-fire research facility; able to characterize the response of full-scale building systems to realistic mechanical loading and fire. The facility maintains an infrastructure of measurements necessary for accurately characterizing the heat release rate of fires, a key parameter in predicting fire hazard. This measurement infrastructure includes four oxygen consumption calorimeters to measure the heat released during fire experiments, and a fuel consumption calorimetry system (natural gas burners and flow control) to generate precise amounts of heat release. Both systems have a heat release rate capacity of 20 MW, twice the capacity of the previous facility. A rigorous evaluation of the processes for the measurements by oxygen consumption calorimetry and fuel consumption calorimetry has resulted in significant improvements in measurement uncertainty when compared to previous versions of the facility. Measurement agreement between the two independent systems has been demonstrated and provides evidence that NFRL's system of heat release rate measurements for large-scale fire research are the most accurate and highly characterized of their kind. The methodology, hardware, and performance of the large-fire calorimeters and natural gas flow system are described here to provide technical guidance on achieving accurate heat release measurements to laboratories with the mission of accurate large-scale fire testing.

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In this study, distributed fiber optic sensors based on pulse pre-pump Brillouin optical time domain analysis (PPP-BODTA) are characterized and deployed to measure spatially-distributed temperatures in reinforced concrete specimens exposed to fire. Four beams were tested to failure in a natural gas fueled compartment fire, each instrumented with one fused silica, single-mode optical fiber as a distributed sensor and four thermocouples. Prior to concrete cracking, the distributed temperature was validated at locations of the thermocouples by a relative difference of less than 9 %. The cracks in concrete can be identified as sharp peaks in the temperature distribution since the cracks are locally filled with hot air. Concrete cracking did not affect the sensitivity of the distributed sensor but concrete spalling broke the optical fiber loop required for PPP-BOTDA measurements.

An experimental study of the bench-scale fire performance of 18 commercial polymeric materials was conducted by the National Institute of Standards and Technology. The performance of these materials was characterized using three standard flammability tests. The ignition resistance, self-extinguishing behavior, heat release rate, and combustion product yields for these burning materials were evaluated at two material thicknesses and are discussed in terms of fire safety. This report details the first of a two part study in which the relationship between bench-scale and full-scale fire performance will be examined. Several of the materials characterized in this report will be selected for use in the full-scale study.

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