Three photometers are available:
A rotating mirror goniometer used for smaller sources such as HID, incandescent and compact fluorescent. It has a range of 15 feet and used for luminaires with maximum dimensions less than 3 feet.
The goniometer for larger sources such as fluorescent and low pressure sodium has a 26-foot range utilizing multiple cells mounted at 5-degree intervals. All cells are individually, electrically matched to a standard source which allows absolute as well as relative photometry with both goniometers.
A near-field photometer is available for task lights, indirect luminaires and units that are mounted in close proximity to the object being illuminated.
Data acquisition is with state of the art analog to digital converter setup to take sample readings to avoid errors caused by inconsistencies in output waveforms.
We have a LabSphere CSLMS-7621 Integrating Sphere for absolute photometry of lamps, luminaires and solid state lighting products (LED). LED luminaires are tested to IES standard LM-79. This allows us to give you the chromaticity information (Corrected Color Temperature, Color Rendering Index, Total Luminous Flux, Spectral Power Distribution and Luminous Efficacy). Calibration of the Spectroradiometer/Sphere system is tracable to NIST standards.
Luminaires are tested in their normal burning position. The laboratory is designed to maintain a temperature of 25 degrees centigrade (celsius) with air flow not exceeding 30 feet per minute at test sample.
Far-field photometry assumes the luminaire to be a point source. We need to be at least 5 times the greatest dimension of the luminaire for this. This data can be applied to any application and is the most widely used.
Near-field data is application specific and the data is only valid for the distance at which it was tested.
What does all this photometric stuff mean?? and How do I read a photometric file? (you will need Acrobat Reader to view this file)
If you don't have this go get it now -