Oxygen consumption calorimetry

Oxygen consumption calorimetry with E = 13.1 kJ/g is used to measure heat release rate as a function of time. The specific heat release rate, Q(t), in W/g is equal to the heat release rate divided by the initial specimen mass, mG. The following live parameters are calculated when... 

During the cone calorimeter experiment, the main result of heat release, especially HRR8187 and THR, is determined by oxygen consumption calorimetry.88 89 In due course, different types of typical burning behavior give rise to characteristic curves of HRR. Some are illustrated schematically in Figure 15.6 81... 

Janssens M, Parker WJ. Oxygen consumption calorimetry. In Heat Release in Fires. Babrauskas V, Grayson SJ, Eds. Elsevier Science Publishers Barking, U.K., 1992 chap. 3, pp. 31-59. 

Simplified cone calorimeters have been suggested for quality assurance testing in which mass.doss and/or temperature measurements replace the more complex oxygen consumption calorimetry. Published specifications for the cone calorimeter include... 

The new UL test method utilises a collection hood and duct system prescribed under various nationally recognised fire test procedures including the UL 1715 Standard [54]. The test structure is a masonry room measuring 2.4 m wide by 3.7 m long by 2.4 m high, with one 2.4 m wide open end. Heptane fuel burners are used to provide the internal fire source. The test method utilises oxygen consumption calorimetry to quantify the roof covering materials. 

The trials undertaken to calculate the HRR have shown that this parameter can be used to obtain an adequate correlation of the course of burning of the belt in the full-scale gallery fire test. This makes it possible to develop a fast method of testing the flammability of conveyor belts by oxygen consumption calorimetry. 

Chemical heat release rate is the actual heat that is released in the combustion of a polymer [21, 22]. It has a convective and a radiative component. Chemical heat release rate is always less than the heat release rate for complete combustion as the polymers do not burn completely. Chemical heat release rate is determined from the mass generation rate of CO2 corrected for the mass generation rate of CO (defined as the caibon dioxide generation calorimetry) and from the mass depletion rate of O2 (defined as the oxygen consumption calorimetry). 

Calorimeter for oxygen consumption calorimetry PL Thermal Sciences Mettler Instruments Perkin Elmer Corp. Fire Testing Technology... 

The resultant equations are not necessarily simple, but they have been worked out in detail by Parker [48] for most conditions of concern. These equations are the starting point for the implementation of apparatuses based on oxygen consumption calorimetry. 

Siat, C. Bourbigot, S. Le Bras, M. Combustion behaviour of ethylene-vinyl acetate copolymer-based intumescent formulations using oxygen consumption calorimetry. 

The versatility and accuracy of the oxygen consumption method in heat release measurement was demonstrated. The critical measurements include flow rates and species concentrations. Some assumptions need to be invoked about (a) heat release per unit oxygen consumed and (b) chemical expansion factor, when flow rate into the system is not known. Errors in these assumptions are acceptable. As shown, the oxygen consumption method can be applied successfully in a fire endurance test to obtain heat release rates. Heat release rates can be useful for evaluating the performance of assemblies and can provide measures of heat contribution by the assemblies. The implementation of the heat release rate measurement in fire endurance testing depends on the design of the furnace. If the furnace has a stack or duct system in which gas flow and species concentrations can be measured, the calorimetry method is feasible. The information obtained can be useful in understanding the fire environment in which assemblies are tested. 

Non-invasive assessments of mitochondrial function in vivo typically reflect the techniques to monitor it in cells or isolated organelles. Direct calorimetry, organismal oxygen consumption, CO2 production and a host of other techniques all provide insight into mitochondrial capacity, albeit with confounding factors of movement and physical training of the subject. 

The use of direct calorimetry is not a convenient technique, since it requires a specially constructed room and the confinement of human subjects for a day or longer in the room. The doubly labeled water technique offers a convenient alternative, providing that one has a machine to perform isotope ratio mass spectrometry. The doubly labeled water technique is used to measure the rate of total CO2 production in the body. This number alone is not sufficient to allow one to calculate the total energy expenditure. But the value for COj production (moles COi/day), along with the RQ, allows one to calculate the oxygen consumption using the following formula ... 

In the studies described in this section, metabolic rate was measured indirectly by oxygen consumption. True metabolic rates (heat generated per unit time) are measured by calorimetry which... 

Indirect calorimetry, a technique that measures Oj consumption and COj production, can be used when more accurate determinations are required for hospitalized patients. A portable indirect calorimeter is used to measure oxygen consumption and the respiratory quotient (RQ), which is the ratio of Oj consumed to COj produced. The RQ is 1.00 for individuals oxidizing carbohydrates, 0.83 for protein, and 0.71 for fat. From these values, the daily energy expenditure (DEE) can be determined. 

E 1269 (1999) Test method for determining specific heat capacity by differential scanning calorimetry E 1354 (1994) Test method for heat and visible smoke release rates for materials and products using an oxygen consumption calorimeter... 

As a consequence of a very serious fire under the steel roofs in a large car plant in USA the Underwriters Laboratories Inc., developed a new UL test method, which uses oxygen consumption cone calorimetry to quantify roof covering materials. This test was used to quantify the contribution of roof covering materials to the fire under the roof by capturing effluent from beneath the roof assembly and recording the rate of heat production in kW/min. 

The chemical heat release rate is determined from the carbon dioxide generation (CDG) and oxygen consumption (OC) calorimetries [2,3]. In the CDG calorimetry, the chemical heat release rate is determined from the mass generation rate of CO2 corrected for CO [2,3]. In the OC calorimetry, the chemical heat release rate is determined from the mass consumption rate of O2 [2,3,24]. The convective heat release rate is determined from the gas temperature rise... 

Experimental values for hc° determined by pyrolysis-combustion flow calorimetry (see below) are listed in Table 7. The elemental analysis of chars gives typical chemical formula C5H2 from which the heat of combustion of the char calculated from oxygen consumption is /ic,p° 37 kJ/g, which can be used to estimate the heat of combustion of the fuel gases of charring polymers using equation 56 if /x is known. 

Instrumentation for the measurement of the flammability characteristics of polymers intended for use in mining, electrical, transport, furniture, construction materials is discussed in Chapter 17, including methods of identifying combustion products and the measurement of oxygen consumption by oxygen cone calorimetry. New methods based on pyrolysis - gas chromatography - mass spectrometry and laser pyrolysis time of flight mass spectrometry are also discussed. 

This is a much more complex test than those described previously, and is thought to come closer to real fire conditions. The method is based on what is known as oxygen depletion (or consumption) calorimetry. The development of the method has been... 

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