The Absolute Integrating Sphere Method is now used at NIST for the detector-based calibration of total luminous flux of lamps, as well as for the realization of the lumen. This method has many benefits for high-accuracy applications, allowing for measurement of total luminous flux based on an illuminance standard photometer, not requiring use of total luminous flux standard lamps, thus eliminating uncertainties associated with the transfer process and aging of the working standard lamps. This method requires calibration of many components in the sphere system and is not suited for industrial laboratories. To avoid this difficulty, a new approach for industrial use of this method is proposed. An absolute integrating sphere system of the same design as that of NIST can be calibrated directly against the total luminous flux standard lamps from a national laboratory, with no need for characterization of all the parameters required for the absolute sphere method, and still allows for the same detector-based measurements with all the benefits to achieve lower uncertainties. The principles of this approach and experimental plans for an absolute integrating sphere being built at GE Lighting are presented.
Citation: Journal of Research (NIST JRES) -
Volume: 107 No. 4
NIST Pub Series: Journal of Research (NIST JRES)
Pub Type: NIST Pubs
C-centered cell, centered monoclinic cells, conventional cells, I-centered cell, mathematical lattices