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The feasibility of an EXAP procedure for copper communication cables (CCC) has been investigated. The test set consisted of 47 different cables split into 9 families. An analysis method for quantifying the confidence of an EXAP procedure was defined.A similar EXAP procedure as for power cables was investigated, but where the safety margin sm was varied between 0% and 40% of the class limits for the corresponding Euroclasses. For power cables, and also for optical cables (OF) this safety margin was fixed to 10% of the class limits for the main classification (B2ca, Cca, and Dca) and 20% fire the smoke classes S1 and S2. For the analysed CCC it was found that the safety margin must be higher in order to obtain a confidence on the same level as for the OF EXAP already published in a Position Paper. The error rate for the OF EXAP was 2% for the main class. This error rate was obtained with a safety margin of 30% of the class limits for CCC. Even higher safety margins result in a lower error rate but a trade-off must be made between confidence in the EXAP and a reasonable, not too conservative, classification of CCC.Therefore a CCC EXAP is proposed with a safety margin sm = 30% of the class limits for the corresponding Euroclasses.Key words: EXAP, CPR, reaction to fire, copper communication cables, CCC

A continuous current with a potential ranging between 10 and 30 kV was applied to a single-hole nozzle for modifying the properties of the generated water spray. The nozzle produced a full-cone spray by injecting water into quiescent air at atmospheric conditions varying the injection pressure between 0.2 and 0.6 MPa. Back-illuminated photography and laser-based holography were used for recording the effect of the electrical current on spray properties such as cone angle and droplet sizes. Results from this study indicate that applying a potential above 20 kV yields wider cone angles, more homogenously distributed spray patterns, and reduced droplet sizes than non-assisted sprays.Key words: electrosprays, water mist

In-line holography, where the reference beam coincides with the beam that is scattered against the droplets, has been found to be a versatile and simple experimental method for spray diagnostics using holography. Such an experiment was setup and a water spray was studied and holograms of high quality was obtained using a CCD-camera. The holograms were analysed with Wavelet analysis, implemented as a Matlab program. It was found that the droplets’s size and position could be reconstructed with reasonable accuracy. Future work will focus on a dynamic analysis program that dynamically adapts the wavelet analysis parameters to each detected droplet. Key words: spray diagnostics, laser diagnostics, holography, image processing, wavelet analysis

Infrared Polarization Spectroscopy (IRPS) was used to detect and quantify HCl and HCN in an 800 mm long tube furnace. Pieces of a PVC-carpet or pellets of nylon 6,6 were continuously fed into the furnace producing a heavy smoke. This constitutes a very harsh environment from a diagnostic point of view due to the high smoke density and relatively long length of the furnace. Despite this it was possible to quantify HCl and HCN concentrations in the smoke down to a levels of 50 ppm using IRPS. The explanation for this success is twofold. Firstly the IRPS method is inherently almost noise free due to the use of crossed polarisers, creating a virtually zero background. Secondly the problem with laser beam attenuation due to scattering in the smoke, especially with soot particles, decreases in importance with the fourth power of the laser wavelength. This means that infrared measurements represent a great advantage over measurements in the ultraviolet or visible wavelength range. It is concluded that IRPS shows great promise as a new diagnostics tool in fire technology for small-scale as well as for large scale experiments. Furthermore the in situ nature of the method should be emphasized since this means that valuable information is obtained that can not be extracted from sampling methods such as MS/GC or FTIR for example. This information is important, for example, in egress calculations and analysis of fire chemistry. The method can easily be adapted for other gases such as HF, NO, NO2, HBr, CO and SO2.

Vid en brand, eller incident som kan leda till brand, ger en tidig upptäckt och omedelbar åtgärd en minimerad skadebild. De flesta ställverk är obemannade. Det förekommer underhållsverksamhet under begränsad tid men till största delen har ställverken ingen personal på plats. Många anläggningar ligger också långt från tätbebyggt område vilket medför långa insatstider för räddningstjänsten och ansvarig personal. Vår utgångspunkt är därför att föreslå åtgärder som ger minsta möjliga stilleståndstid vid brand eller incidenter som kan leda till brand. Det är också viktigt att kunna övervaka och styra skeenden på distans. Resultatet av denna studie kan sammanfattas i följande rekommendationer. 1. Möjliggör tidig upptäckt med hjälp av högklassig detektionsutrustning. 2. Möjlighet att omedelbart identifiera problemet, från bemannad station, exempelvis via fjärrkamera. 3. Möjlighet att koppla bort problemområdet från kraftkällan efter identifierad incident. 4. Det bör finnas släcksystem som aktiveras automatiskt via detektion eller manuellt (fjärrutlösning). 5. Man bör använda släckmedel för relärum som inte skadar elektronikprodukter. 6. Täta genomföringar för att förhindra brandspridning och skadlig påverkan av brandgaser i angränsande rum. 7. Man bör utveckla släcksystem för transformatorer som kan aktiveras innan brand utbryter. 8. Möjliggöra access även i strömlöst tillstånd 9. Särskilja redundanta system 10. Viss överkapacitet på transformatorn Det har visat sig mycket svårt att få en tydlig bild av förekomsten av bränder eftersom de tillfrågade parterna, typiskt kraftbolag, endera inte har någon tillfredställande dokumentation över tillbud, eller har som policy att inte lämna ut den typen av uppgifter. Förbättrade rutiner för dokumentation av tillbud är en förutsättning för en långsiktig förbättring av brandskyddet. Kunskapen om bränder och explosioner i transformatorer är mycket mer begränsad än bränder i byggnader och liknande. Därför behövs ytterligare studier av de mekanismer som föregår och orsakar en transformatorexplosion. Vi föreslår ett antal forskningsprojekt i syfte att kartlägga dessa mekanismer. I förlängningen kan detta resultera i system som förhindrar eller begränsar konsekvenserna av det som idag leder till att transformatorer exploderar.

Measurements of the ion current between two electrodes have been conducted in a premixed propane flame and in a cone calorimeter in order to assess whether the ion current can be used for combustion diagnostics in general and for detection of ignition in a cone calorimeter in particular. It was seen that the ion current responds distinctly to where it is positioned in a propane flame and also to the fuel/air ratio of the flame. In the cone calorimeter the measured ion current shows clearly when ignition occurs. The ignition detected by the ion current measurement agreed with visual inspection. It was also seen that soot deposits on the electrodes do not affect the ion current in such a way the ignition detection could be jeopardized. However, short circuiting could occur if the electrodes were kept in a sooty flame long enough for the soot to completely bridge the gap between the electrodes. The latter scenario is not a problem from an ignition detection point of view since soot growth occurs after ignition has taken place. The general conclusion from the study is that no unforeseen obstacles with the use of ion current measurements in combustion diagnostics were observed.