Integrating Sphere Selection for the LAMBDA 1050+: Size and Detector Comparison

Introduction

Integrating spheres are essential for measuring total reflectance and transmittance of materials that scatter light, including architectural and automotive glass, optical coatings, polymers, ceramics, papers, and technical textiles, where standard detectors or specular geometries fall short. By collecting and spatially integrating light reflected or transmitted in all directions, an integrating sphere delivers reliable total reflectance and transmittance data.

Sphere diameter, port fraction, and detector type/location directly affect collection uniformity, signal-to-noise ratio, and spectral sensitivity. These factors become especially critical when measuring materials with widely varying reflectance levels, where detector linearity and sphere throughput drive measurement accuracy and repeatability.

This technical note compares three integrating sphere and detector configurations on the PerkinElmer LAMBDA^® 1050+ UV/Vis/NIR Spectrophotometer for diffuse reflectance measurements:

• 150 mm PMT/PbS Integrating Sphere
• 100 mm PMT/InGaAs Integrating Sphere
• 150 mm PMT/InGaAs Integrating Sphere