METHOD FOR NONDESTRUCTIVE TESTING OF THERMAL PROPERTIES OF BUILDING ENVELOPES Russian patent published in 2013 - IPC G01N25/18 G01N27/22 

FIELD: measurement equipment.

SUBSTANCE: method for nondestructive testing of thermal properties of building envelopes consists in the fact that actual values of thermal conductivity are measured in the inner and outer surface layers of the envelope. Then values of resistances to heat transfer in these layers are calculated in accordance with the following formulae: R_I=δ_I,λ_I and R_O=δ_O,λ_O, where R_I and R_O - values of resistances to heat transfer in inner and outer surface layers of the envelope, accordingly; δ_I and δ_O - thickness of inner and outer surface layers, accordingly; λ_I and λ_O - thermal conductivity of inner and outer surface layers, accordingly. Further the value of resistance to heat transfer in the thermal insulation layer is calculated in accordance with the following formula: R_T=R_E-1/α_I-1/α_O-R_I-R_O, where R_T - resistance to heat transfer of the thermal insulation layer; R_E - total resistance to heat transfer in the envelope; α_I, α_O - coefficients of heat emission in inner and outer surfaces of the envelope, accordingly. Then the actual value of thermal conductivity is calculated in the material of the thermal insulation layer of the envelope in accordance with the formula: λ_T=δ_T/R_T, where λ_T - thermal conductivity of the material; δ_T - layer thickness. Then the actual value of moisture is defined in the material of the thermal insulation layer in accordance with the following formula: w_T=(λ_T-λ₀)/Δλ_W, where W_T - moisture of the material; λ₀ thermal conductivity of the material in dry condition; Δλ_W - increment of material thermal conductivity by 1% of moisture.

EFFECT: determination of thermal characteristics of a thermal insulation layer of multiple-layer building structures without damage of their integrity.

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