A	Area of the copper plate (0.002515)	m2
a	Area of the measuring cup opening	m2
C p	The specific heat of copper (0.385)	kJ/kg°C
T	Thickness of fabric	mm
Dwa	Density of the warp threads	threads/cm
Dwe	Density of the weft threads	threads/cm
L t	Latent heat of evaporation of water at temperature t	Wh/g
M	Surface mass of fabric	g/m2
Mbp	Mass of copper plate (0.036)	kg
M 0	Mass of the measuring cup before testing	g
M 15	Mass of the measuring cup after testing	g
P	Fabric volume porosity	(%)
psa	Saturated water vapor pressure at the test room temperature Ta	Pa
psb	Saturated water vapor pressure at the water bath temperature Tb	Pa
R et	Water vapor resistance	m2Pa/W
RH	Relative humidity in equilibrium with saturated potassium acetate solution	%
RHTI	Mean time measured	s
RHTI24 − RHTI12	A difference of measured times for temperature rise of 24 and 12 °C	s
T a	The temperature in the test room	°C
T b	The temperature in the water bath	°C
T 12	The time required for the temperature rise of 12 °C	s
t 24	The time required for the temperature rise of 24 °C	s
TFQ 0	Heat transfer factor	kW/m2
WVP	Water vapor permeability of the specimen	g/m2Pah
WVP app	Apparatus water vapor permeability	g/m2Pah
QC	Leaked heat flux density through the sample to the calorimeter	kW/m2
Q 0	Default heat density (radiation source per calorimeter)	kW/m2
qfabr.	Volume density of the fabric	g/m3
qfibr.	Specific fiber density (M-aramid = 1.38 g/m3)	g/m3
ΔM	Change in the mass of the measuring cup during the period ∆t	g
Δmapp	Change in the mass of the measuring cup on the specimen holder with membrane only during the period of Δt	g
Δp	Partial water vapor pressure difference across the specimen	Pa
Δt	Measuring time	h