Integrating sphere introduction

The recent years has witnessed the fast development of Integrating sphere, it is one of the most important device for spectral and luminous flux measurement of light source. it is widely applied in the photometric and colorimetric test system in led measurement applications.The inside surface of an integrating sphere is coated with a diffusely reflecting material which guarantees complete integration and homogenization of the emitted radiation.The Integrating sphere is an important instrument of optical measurement for enabling high sensitivity measurements. The sphere is made of a sintered PTFE, which is >98% reflective in the visible.

Each of the integrating spheres can couple to our spectrometers to measure the total integrated reflectance of surfaces placed against the sphere's sample port.Integrating spheres generally function as a light collector. The collected light can be used as a diffuse illumination source or as a measurement source.In the Avantes line of integrated spheres the spheres are mostly used as measurement source. The basic principle of operation is that light enters the integrating sphere through the sample port, goes through multiple reflections and is scattered uniformly around the interior of the sphere. The detection fiber optics are SMA-coupled to the port at the side of the sphere which is viewing illumination on a baffle, independent of the angular properties of the light at the sample port. The baffle prevents first reflections to enter the detection fiber.

A compact and affordable luminaire goniophotometer

A compact and affordable luminaire goniophotometer which generates standard IESNA & EULUMDAT photometric files The PM-NFMS from Radiant Imaging combines a motorised goniometer stage with a ProMetric CCD imaging photometer to perform a near-field angular analysis of the luminance and colour from LEDs, luminaires and solid state lighting.

 

ProSource software then scales this to far-field luminous intensity data from which standard photometric files are generated.So-called photometric data defines how much light a luminaire emits and into what directions; lighting designers then use this standardised data format with all kinds of commercially-available lighting design programmes to determine the number and positioning of luminaires in order to create the desired illuminance.

The Integrating Sphere system has been designed and constructed according to the specifications detailed in the following paragraphs.

The Integrating Sphere  system has been designed and constructed according to the specifications detailed in the following paragraphs. The inside wall of the sphere is coated with a material that is nearly a Lambertian diffuser and at the same time has a high directional hemispherical diffuse reflectance! The sphere has entrance, sample, and reference ports, all centered on a great circle of the sphere,. There is also a detector port, with its center located along the normal to the great circle. An integrating-sphere system is designed and constructed for measuring a variety of optical properties in the IR spectral range. Integrating spheres are also applied to an averaging device for detectors. Due to the helpful propertities of an integrating sphere, an averaging sphere’s entrance port can be significantly larger and spatially uniform. The benefits of using an integrating sphere for detecting light more accurately are used in the design of system and development of the method. The measurement of absolute transmittance, reflectance, and absorptance of specular samples is described and demonstrated.