What is PD CEN/TR 16988- Single burning item test about?
PD CEN/TR 16988 is a safety standard on the estimation of uncertainty in the single burning item test.
The measuring technique of the SBI (single burning item) test instrument is based on the observation that, in general, the heats of combustion per unit mass of oxygen consumed are the same for most fuels commonly encountered in fires (Huggett [12]).
The mass flow, together with the oxygen concentration in the extraction system, suffices to continuously calculate the amount of heat released. Some corrections can be introduced if CO2, CO, and/or H2O are additionally measured.
The main calculation procedures for obtaining the HRR and its derived parameters are summarized here for convenience. The formulas will be used in the following clauses and especially in the clause on uncertainty. The measured data are synchronized making use of the dips and peaks that occur in the data due to the switch from ‘primary’ to ‘main’ burner around t = 300 s, i.e., at the start of the thermal attack to the test specimen. Synchronization is necessary due to the delayed response of the oxygen and carbon dioxide analyzers. The filters, long transport lines, the cooler, etc. in between the gas sample probe and the analyzer unit, cause this shift in time.
Who is PD CEN/TR 16988- Single burning item test for?
PD CEN/TR 16988 on the estimation of uncertainty in the single burning item test is relevant to:
- Manufacturers of construction products
- Testing authorities of SBI test
Why should you use PD CEN/TR 16988- Single burning item test?
It is considered good practice to eliminate any systematic errors. However, if the value of a systematic error is unknown it may be regarded as a random error.
PD CEN/TR 16988 is about the estimation of uncertainty in the single burning item test. Often the standard deviation σ is unknown. To evaluate the confidence interval, some estimate of σ shall be made. The most obvious candidate is the sample standard deviation s. But the use of s introduces an additional source of unreliability, especially if the sample is small. A population with a ‘normal’ probability density function is characterized by its mean value μ and its variance σ2: N(μ,σ2). The rectangular distribution is a reasonable default model in the absence of any other information. But if it is known that values of the quantity in question near the centre of the limits are more likely than values close to the limits, a triangular or a normal distribution might be a better model.
Overall, PD CEN/TR 16988 is useful as it provides guidance on the estimation of uncertainty in the single burning item test.
