Fast testing of building glass emissivity using Fourier transform infrared spectrometer

laboratoryFTIRWQF-530

1.Preface

according to2021Published annually《Measurement of Visible Light Transmittance, Direct Solar Transmittance, Total Solar Transmittance, Ultraviolet Transmittance, and Related Window Glass Parameters for Architectural GlassHow to translate.5The Fourier transform infrared spectrometer at the Raleigh Laboratory of the North Branch caninWithin minutesachieve

2.Radiance rate of hollow building glass (two glass and one cavity, three glass and two cavities)Perform spectral detection and use specialized software to directly provide the heat transfer coefficient.

Fourier transform infrared spectrometerApplicable standardØ

GB/T 2680-2021Measurement of Visible Light Transmittance, Direct Solar Transmittance, Total Solar Transmittance, Ultraviolet Transmittance, and Related Window Glass Parameters for Architectural GlassØ

JGJ/T 151-2008Thermal Calculation Code for Building Doors, Windows, Glass Curtain WallsØGB/T 22476-2008Steady state of insulating glass

UCalculation and measurement of heat transfer coefficientØISO15099-2003Thermal performance of doors, windows, and shading devices

3.-

Detailed calculationinstrument and equipmentØhost:W

QF-530Laboratory Fourier Transform Infrared SpectrometerØAttachment: Mirror reflection attachment (including standard)

Aluminum plated reflectionLens)

4.Ø

Specialized software: Fourier transform infrared emissivity measurement system4Test PrincipleWhen radiation energy is incident on the surface of an object, it undergoes three processes: absorption, transmission, and reflection. Due to the presence of glass5 mmThe above passage is zero, so it can pass through when in thermal equilibriumtestglassReflectance is used to indirectly test itradiation

5.rateThen calculate the heat transfer coefficient by emissivity.

5.1Fourier transform infrared spectrometer

test methodtest conditions

ØMeasurement mode: Reflection2.5ØWavelength range:~25μm（^-14000-400

cm）Ø^-1

Sampling resolution:4cm16Ø

Scanning frequency:time25ØSample requirement: Size greater than25mm

5.2×

mmtest processFirstly, place the polished aluminum reflector in the sample hole of the mirror reflection attachment to test the background spectrum; Subsequently, place the glass sample to be tested in the sample hole of the mirror reflection attachment to test the sample spectrum; Finally, Fourier transform infrared emissivity is usedDirectly provided by dedicated software

6.Radiation rate and heat transfer coefficient

6.1result

Test resultsRadiation rate testThe software can be used according toGB/T 2680-2021andG

6.2B/T 22476-2008

The method directly calculates the corrected emissivity of any side of the glass.Calculation of heat transfer coefficientTwo glasses and one cavitylow-e0.841glass0.841Provide an example for illustration. After opening the emissivity curves of two glass pieces on all four sides directly with software, first calculate the four corrected emissivity values0.139、0.841、、Further according toG1.851B/T 22476-2008

7.The heat transfer coefficient calculated by the given method is

.Conclusion