DW259A SWEATING GUARDED HOTPLATE DW259A

DW259A SWEATING GUARDED HOTPLATE - DW259A

1.water-vapor permeability, 2.partial discharge (corona), 3.thermal transmittance - more info check here: http://www.buymeasuringtools.com/DW259A-SWEATING-GUARDED-HOTPLATE-10346592/

Quick Brief

Place of Origin: Hong Kong Brand Name: FYI Model Number: DW259A Power: Electronic Usage: SWEATING GUARDED HOTPLATE Testing equipment: SWEATING GUARDED HOTPLATE

Specifications and Product Details:

MODEL NO.

DW259A

APPLICATION

DW259A Sweating Guarded Hotplate is often referred to as “skin model” to produce accurate, repeatable measurements of thermal resistance and water vapor resistance of textiles, fabrics, films, coatings, foams and leather including multilayer assemblies, such as clothing, quilts, sleeping bags, upholstery and similar textile or textile-like products under steady-state conditions.

The specimens to be tested is placed on an electronically heated porous plate with conditioned air ducted to flow across and parallel to its upper surface.

Thermal resistance(Rct): a quantity specific to textile materials or composites which determine the dry heat flux across a given area in response to a steady applied temperature gradient, expressed in square meters kelvin per watt.

Rct=(Tm-Ta)*A/(H-ΔHc)

Tm: the temperature of the measuring unit, in degree Celsius;

Ta: the air temperature in the test enclosure, in degree Celsius;

A: the area of the measuring unit, in square meters;

H: the heating power supplied to the measuring unit, in watts;

ΔHc: the correction term for heating power;

Water vapor resistance(Ret): a quantity specific to textile materials or composites which determines the “latent” evaporative heat flux across a given area in response to a steady applied water-vapor pressure gradient, expressed in square meters pascal per watt.

Ret=(Pm-Pa)*A/(H-ΔHe)

Pm: the saturation water-vapour partial pressure, in pascals, on the surface of the measuring unit at temperature Tm;

Pa: the water-vapor partial pressure of the air in the test enclosure at temperature Ta;

A: the area of the measuring unit, in square meters;

H: the heating power supplied to the measuring unit, in watts;

ΔHe: the correction term for heating power for the measurement of water-vapor resistance Ret;

Water-vapor permeability index, i_mt: ratio of thermal and water-vapor resistance;

i_mt=S*(Rct/Ret)

S equals to 60Pa/k;

Water vapor permeability, W_d: characteristic of a textile material or composite;

W_d= 1/(Ret*Tm);

Tm: the latent heat of vaporization of water at the temperature Tm of the measuring unit;