Clothing Test Methods, Edited by L.H. Newburgh (Physiological Tests) and Milton Harris (Physical Tests) of Subcommittee on Clothing of the National Research Council (U.S.A.) (1945) / Chapter Skim
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Definition of Adequacy (Siple)
Definition of Adequacy (Siple)
Pages 65-98
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From page 65... ...
2. Adequate Protection for Sleeping Men The following definition of adequate protection for sleeping men is proposed: Sleeping gear should be considered adequate if it provides eight hours comfortable sleep at the average minimum temperature of the environment.
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From page 66... ...
The charts and subsequent discussion of clo values apply to dry clothing only. At the present time, no standard of the decrease in adequate protection afforded by damp clothing can be analyzed.
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From page 67... ...
rH 03 TH cd * rH Q-l o oo r^oo ^-H ojtfN m m t -- o\ co H -P fH 0 1 It^^J-rHOChOAO^OrH OJKN-^-in 0 O C £> P t -- rHHrH rHrH rHrHrHrH 0 ,0 TH TH 0 0)
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From page 70... ...
DEFINITION OF ADEQUACY OF CLOTHING IN COLD CLIMATES 71 ACTIVITY - 40 KG CALS./M'/hr SLEEPING HEAT LOSS- 40 KG.
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From page 71... ...
72 CLOTHING TEST METHODS Kg. cols./ME/hr.
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From page 72... ...
PART II Physical Teat Methods
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From page 74... ...
Thermal insulation 15- Resistance to diffusion of water vapor 16. Rate of drying 17- Air permeability I
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4. Test Methods and Ratings, by A
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C Goodings: In testing work which we have been carring out for the R.C.A.F., we have been using the tongue test method as a measure of the tear strength.
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The Vyzenbek machine is also in use at the National Bureau of Standards. The following description is taken from "Test Methods and Ratings," by A
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From page 78... ...
project, the objects being as follows: a. To develop methods of measuring the degree of wear suffered by garments subjected to the test combat course.
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From page 79... ...
a. Measurement of socks: These measurements were made with a special device designed by the Textile Section of the National Bureau of Standards.
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J Research National Bureau of Standards 29, 69-71 (July 1942)
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From page 81... ...
Hoops carrying the material to be tested are revolved at various controlled speeds past a lighted gas jet directed at them horizontally. The gas jet consists of a micro burner for which the gas is supplied at controlled pressure (9 cms.
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From page 82... ...
Further tests were developed in which the test fabric was backed by some material such as nylon which would act as an indicator of temperature on the side of the fabric remote from the flame and permit a time evaluation of how long it took for a fabric exposed to a standard flame to reach a certain temperature. This, however, is not the whole story because it obviously is an important difference whether a fabric will ignite and blaze or whether it will not.
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From page 83... ...
The distinction should be observed between water proof fabrics in which a continuous film of water proof material, such as rubber, is supported by the fibers, and water repellent fabrics, in which the space between the fibers is not closed, but the surface characteristics have been altered to prevent wetting. The following discussion is primarily concerned with water repellent fabrics.
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From page 84... ...
The SchIefer-Boyland air permeability apparatus developed at the National Bureau of Standards, appears to be the most suitable machine available for routine laboratory use. Of the simple routine tests, the hydrostatic pressure tests (group 3)
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A cylindrical bag approximately 3i" in diameter and 4" in height is filled with the fibre to be examined, the weight of fibre per cubic foot to be used having been determined in the manner described under (a) above.
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From page 86... ...
It has been shown that for most textile materials where the bulk density is above a certain minimum figure, that is, where the air spaces trapped by the fibers are quite small, that the thermal insulation is practically proportional to the thickness. This makes it possible to calculate the thermal transmission simply from the thickness.
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From page 87... ...
Larose; As already indicated, thermal transmission depends on thickness and therefore a compressible material will have a varying degree of thermal insulation, depending on the pressure imposed. Since certain parts of the clothing are.under pressure during use, it is important to gain an idea of the compressibility of the clothing materials in order to determine the relative merits in respect fo thermal insulation.
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From page 88... ...
THERMAL INSULATION. A guarded hot plate method is used as the fundamental standard in both the United States and Canada.
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Hence, to obtain intrinsic resistance from National Bureau of Standards thermal transmission values, one should: (a) take the reciprocal of the thermal transmission; and (b)
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From page 90... ...
It is agreed that the values for the water vapor permeability of fabrics should be given in terms of an equivalent thickness of ideal still air. This would appear to be a very useful method of expressing results because where one is dealing with several layers of clothing with air layers in between, the total resistance of clothing to the passages of water-vapor can be arrived at by the summation of the separate resistances.
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From page 91... ...
The total resistance, R, of a system is given in equivalent centimeters of ideal still air, in terras of Q, the grama of water vapor passing, D, the .diffusion coefficient, C, the difference in vapor concentration in grams/cm3, A, the area in cm and t, the time in seconds, by the equation R = ~ A t (1)
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From page 92... ...
The dishes are inverted so that the drying agent is in contact with the fabric, minimizing the path of the water vapor. The inverted dishes are placed on a wide mesh wire rack in a uniform current of conditioned air (70°F, 65$ RH, 200 ft/min has been used)
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From page 93... ...
For the purpose of calculating the resistance, it is assumed that evaporation is taking place at room temperature. The actual temperature of the evaporating surface is somewhat below room temperature, and hence the actual concentration difference between saturated vapor at the water surface and the air of the room is less than the assumed, which implies that the actual resistance is somewhat smaller than the calculated resistance.
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From page 94... ...
For many clothing problems it is desirable to convert the total resistance of a system into a permeability, to give directly the grams of water evaporated per square meter per hour, or the evaporative cooling in Kg cal/m2 hr. The chief difficulty is that clothing problems seldom present an isothermal system.
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From page 95... ...
This is necessary because the fundamental processes involved are the transfer of heat into the fabric, and escape of water vapor out of the fabric, these taking place across the "large scale" surface area, that is, the area covered by the cloth. In comparisons of fabrics it is necessary to control the temperature, relative humidity, air movement, manner of exposure of sample, and size and shape of sample .
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From page 96... ...
, at this arbitrary but standard pressure. "Air permeability" as determined on this device, usually implies the standard pressure across the cloth, although other pressures can be used, from 0.01 to 1.0 inch water gauge.
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From page 97... ...
Although the "rating" of air permeability as the flow through the cloth at 0.5 inch water gauge is convenient and widely used, it may give a misleading impression of the amount of air actually moving through fabric under ordinary conditions. To produce a pressure difference equal to 0.5 inch of water by'impact pressure requires a wind of 31-8 miles per hour.
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From page 98... ...
. S LI ta c o m m i 1 1 e e o n 779 oN3 1945 c.i Clothing test methods
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