Glass in building — Determination of steady-state U values (thermal transmittance) of multiple glazing — Heat flow meter method
建筑玻璃——多层玻璃稳态U值(热透射率)的测定——热流计法
Gives a measuring method used to determine the U value (thermal transmittance) of multiple glazing with flat and parallel surfaces. Structured surfaces may be considered to be flat.