1. Rationale
Proposed Revisions to ASTM F1930-12, November 2012 1.Present statement: 4.5 The overall percentage of predicted second-degree, predicted third-degree and predicted total burn injury is calculated by dividing the total number of sensors indicating each of these conditions by the total number of sensors on the manikin. Alternately, the overall percentages are calculated using sensor area weighted techniques for facilities with non-uniform sensor coverage. A reporting is also made of the above conditions where the areas that are uncovered by the test specimen are excluded. This test method does not include the ~12 % of body surface area represented by the unsensored manikin feet and hands. No corrections are applied for their exclusion. Proposed Statement: 4.5 The overall percentage of predicted second-degree, predicted third-degree and predicted total burn injury is calculated by dividing the total number of sensors indicating each of these conditions by the total number of sensors on the manikin. Alternately, the overall percentages are calculated using sensor area weighted techniques for facilities with non-uniform sensor coverage. A reporting is also made of the above conditions where the areas that are uncovered by the test specimen are excluded (see 13.5.1 and 13.5.2). This test method does not include the ~12 % of body surface area represented by the unsensored manikin feet and hands. No corrections are applied for their exclusion. 2. Present statement: 6.1.1 Size and ShapeThe manikin shall be constructed with a head, neck, chest/back, abdomen/buttocks, arms, hands, legs, and feet. The manikins dimensions shall correspond to those required for standard sizes of garments because deviations in fit will affect the results. A male manikin consisting of the sizes given in Table 1 has been found satisfactory to evaluate garments or protective ensembles. Proposed Statement: 6.1.1 Size and ShapeThe manikin shall be constructed with a head, neck, chest/back, abdomen/buttocks, arms, hands, legs, and feet. The manikins dimensions shall correspond to those required for standard sizes of garments because deviations in fit will affect the results. A male manikin consisting of the sizes given in Table 1 has been found satisfactory to evaluate garments or protective ensembles. The sizes for a female manikin have not yet been set. 3.Present statement: 6.2.2.3 The calibration determined in 10.2.1.3 for each sensor shall be recorded and the most recent calibration results used to carry out the burn injury analysis. Proposed Statement: Move statement 6.2.2.3 to 6.3.1 and renumber the present 6.3.1 to 6.3.2 and add information on energy sources to 6.3. 6.3 Thermal Energy (Heat Flux) Calibration SensorUse a traceable heat flux measuring device to calibrate the energy source used to calibrate the thermal energy (heat flux) sensors. Pure radiant, convective or a combination of energy sources have been found effective for these calibrations. Understanding the energy source, thermal energy (heat flux) sensor interaction is critical to obtaining accurate calibrations. A record shall be kept of the sensor calibrations during their operating life. 6.3.1 6.2.2.3 The calibration determined in 10.2.1.3 for each thermal energy (heat flux) sensor shall be recorded and the most recent calibration results used to carry out the burn injury analysis. 6.3.2 6.3.1 DiscussionRefer to E511 for guidance if copper constantan circular foil heat flux transducers are used. 4.Present statement: 6.5.2 Burn Injury CalculationIn addition to calibrating each sensor, calibrate the sensor - data acquisition - burn model as a unit. Expose a randomly selected sensor to a known heat flux and duration that will result in a second-degree burn injury to be calculated by the computer program. Use the known exposure heat flux and determine the time to the onset of a second-degree burn using the human tissue response as described by Stoll and Chianta (1) (see 12.4). The results produced by the computer shall predict a second-degree burn injury (Omega () = 1.0 at the epidermis/dermis interface) within 5 % of the time found by Stoll and Chianta (1). Include the sensor calibration factor determined in 10.2.1.3. Proposed Statement: Move 6.5.2 to 10.2.1.5, and renumber 6.5.3, 6.5.4, 6.5.5 and 6.5.5.1 to be 6.5.2, 6.5.3, 6.5.4 and 6.5.4.1 10.2.1.5 6.5.2 Burn Injury CalculationIn addition to calibrating each sensor, calibrate the sensor - data acquisition - burn model as a unit. Expose a randomly selected sensor to a known heat flux and duration that will result in a second-degree burn injury to be calculated by the computer program. Use the known exposure heat flux and determine the time to the onset of a second-degree burn using the human tissue response as described by Stoll and Chianta (1) (see 12.4). The results produced by the computer shall predict a second-degree burn injury (Omega () = 1.0 at the epidermis/dermis interface) within 5 % of the time found by Stoll and Chianta (1). Include the sensor calibration factor determined in 10.2.1.3. 5.Present statement: 6.6.1.1 DiscussionThere is no limitation on maximum size provided the operators are safely isolated from the chamber during and after the exposure when toxic gases are likely to be present and that still air conditions exist before and after the exposure so as to ensure repeatable flame exposure and data acquisition conditions. Proposed Statement: Strikethrough portion is redundant, it is covered in 6.6.4 6.6.1.1 DiscussionThere is no limitation on maximum size provided the operators are safely isolated from the chamber during and after the exposure when toxic gases are likely to be present. and that still air conditions exist before and after the exposure so as to ensure repeatable flame exposure and data acquisition conditions. 6.Present statement: 12.2.3.2 The incident heat flux is applied only at the skin surface. The energy incident upon the surface of the skin is assumed to be absorbed at the surface and heat conduction is the only mode of heat transfer in the skin and subcutaneous layers (adipose). (1) Assuming heat conduction only within the skin and deeper layers ignores enhanced heat transfer due to changing blood flow in the dermis and subcutaneous layers (adipose). The in vivo (living) values listed in Table 4 are back calculated from the experimental results of Stoll and Greene (3) and numerical extensions by Weaver and Stoll (5). The values account to a large degree for the blood flow in the test subjects. Proposed Statement: add the word Discussion 12.2.3.2 The incident heat flux is applied only at the skin surface. The energy incident upon the surface of the skin is assumed to be absorbed at the surface and heat conduction is the only mode of heat transfer in the skin and subcutaneous layers (adipose). (1) Discussion - Assuming heat conduction only within the skin and deeper layers ignores enhanced heat transfer due to changing blood flow in the dermis and subcutaneous layers (adipose). The in vivo (living) values listed in Table 4 are back calculated from the experimental results of Stoll and Greene (3) and numerical extensions by Weaver and Stoll (5). The values account to a large degree for the blood flow in the test subjects. 7.Present statement: Correct a typing error; Section 13 to Section 12 X1.10 To predict the severity and extent of damage that results from a fire exposure, it is necessary to know the temperature history of the skin layers. The temperature in the skin layers is calculated using a transient, one dimensional variable property heat transfer model, subject to a set of initial conditions and the heat flux and its variation that occurs at the surface of the manikin as discussed in Section 12 13. The thermal energy sensors fitted in the surface of the manikin are used to generate data from which the heat flux at the surface of the skin at each sensor location and its variation with time can be calculated. This information is then used to predict the temperature history of the skin and subcutaneous layers and the extent of skin damage for each sensor location. Details on how to carry out the calculations are included in a series of technical reports from the University of Alberta. (10), (11), (12)
Keywords
fire, flash; flame testing; flammability, textile; manikin, instrumented flammability testing; protective clothing; thermal testing;
Citing ASTM Standards
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