How to Calculate Sweating Guarded Hotplate Testing Result

Sweating guarded hotplate testing result calculation formula:

Thermal Resistance:  Rct = (Tm-Ta) .A / (H- Hc) - Rct0

Dampness:  Ret = (Ps-Pa) .A / (H- He) - Ret0

If necessary, you can calculate other parameters according to the following formula:

Insulation rate: Wr = (1-b / a)%

ASTM F 1868A Rcf = Rct-Rcpb

ASTM F 1868B Ref = Ret-Repb

Breathable index: im = 0.060 Rcf / Ref

Water vapor transmission rate: Wd = 1 / Ret.ΦTm

When Tm = 35 ℃ when, ΦTm = 0.627W.h / g.

Crow value: clo = Rct /0.155 = 6.451 Rct

Thermal conductivity: k = 10-5.d / Rct

Wherein d is the thickness of the material (mm)

                                                        sweating guarded hotplate

Other related symbols and is defined as:

Rct resistance, m2.K / W

Ret dampness, m2.Pa / W

imt breathable index, dimensionless

Rct0 for the determination of the thermal resistance Rct determined instrument constant, m2.K / W

Ret0 for the determination of moisture resistance Ret determined instrument constant, m2.Pa / W

Rcpb bare-board thermal resistance, with Rct0

Repb bare board dampness, with Ret0

Wd water vapor transmission rate, g / m2hPa

ΦTm test plate surface temperature of saturated steam latent heat Tm when, Wh / g

A test board area, m2 sweating guardedhotplate formula

Ta climate chamber air temperature, ℃

Temperature Tm test plate, ℃

Ts hot grommet temperature, ℃

Pa water vapor pressure (in a climate chamber when the temperature Ta), Pa

Pm saturated water vapor pressure (when the surface temperature of the test plate when Tm), Pa

va test sample over the surface of the air velocity, m / s

sv standard deviation of flow velocity va, m / s

Relative humidity R.H.,%

H provided to the test panel heating power, W

                                                     sweating guarded hotplate testing

△ Hc measurement of thermal resistance Rct heating correction amount of power

△ He dampness Ret correction amount determination heated power

α △ Hc calculation of the amount of slope correction

β △ He corrected the calculation of the amount of slope

k Thermal conductivity, W / m.K

d material thickness, mm

Wr Insulation rate

plus a empty plate heat (J / Cm2.S)

b have the test sample plus heat (J / Cm2.S)

clo CLO value, the thermal resistance of a representation unit. At a temperature of 21 ° C, the air flow does not exceed 0.1m / s environmental conditions, meditation (whose basal metabolism of 58 W / m2) feel comfortable when they wear clothing insulation value of 1 Crow (clo) value.

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