Eurolux is renewing its commitment to technical excellence with the acquisition of a GO-2000 Goniophotometer and Integrated Sphere. These instruments will allow Eurolux to provide lighting designers with sufficient information to plan effective lighting solutions utilising Eurolux products.
The GO-2000 Goniophotometer (also known as a Horizontal Goniophotometer) is a supermatic test system for luminous intensity distribution and total luminous flux measurement of various types of luminaires and lamps, including indoor lights, street lights and floodlights.
“It handles Fluorescent, HID, LED and Incandescent sources, producing the photo metrics for any measured luminaire,” explains Shaun Bouchier, director at Eurolux. “We can use this information for research, development, product performance documentation and/or quality assurance. For us, the biggest benefit is the detailed information we can now offer our customers, allowing them to design effective lighting solutions.”
There are two main components to the Goniophotometer: (1) the rotating table that the fixture or lamp is placed on, including the arms on which the luminaire is mounted, (2) a light sensor that measures light output.
The light source (whether in a fixture or not) is placed in the middle of the Goniophotometer, atop the rotating table, which can be adjusted to make sure the luminaire is centred. When the lamp or luminaire is positioned this way, the light reflects directly onto a light sensor at the opposite end of the room.
The arm with the luminaire rotates from 0-360 degrees vertically, and 0-180 degrees horizontally, measuring every 10 degrees vertically or depending on the settings before testing. This measurement also depends on the symmetry of the light source and how detailed the measurements need to be.
“This process is repeated until we obtain a map of the entire lamp or luminaire,” says Bouchier. A complete test takes anywhere from ten minutes to two hours, depending on the detail needed – greater detail takes more time.
The Integrated Sphere allows Eurolux to measure each specific lamp, whether it is LED, Fluorescent, CFL or HID, to determine its exact Kelvin ratings colour temperature, chromaticity coordinates, Rendering Index, Flux Lumens, Lumen efficiency, Lumen power and power factor. “The main difference between the Integrating Sphere and the Goniophotometer is that the sphere only measures the total light output of a lamp and not the direction,” adds Bouchier.
The lamp being tested is placed in the centre of the Integrating Sphere. At one side of the sphere is a light sensor which measures the light output of the lamp. Between the lamp and the light meter there is a baffle to prevent the sensor from seeing any direct light from the lamp.
The inside of the sphere (including the baffle) is coated with a diffuse white reflective coating that reflects all wavelengths equally. “This allows us to get very accurate measurements. The light from the lamp bounces around the sphere until it reaches the light meter,” explains Bouchier.
It is important that nothing else is in the sphere besides the lamp and the baffle. Anything else placed in the sphere, like a fixture, would absorb some of the light. So if anything besides the lamp and baffle is placed in the sphere, not all of the light reaches the light sensor and this can result in erroneous sensor readings. Says Bouchier: “This means that we can only obtain “bare lamp” readings in the sphere.
“Eurolux always aims to improve the customer experience, and we believe this is yet another way of ensuring our clients get all the information they need to make informed choices.”