Analysis of compact and portable goniospectrometer system for test of LED lamps

An experimental investigation of a compact and portable goniospectrometer system is described. Measurements are performed in two very different conditions, in a normal office environment and in a photometry laboratory under standard environmental conditions and both are compared to reference measurements in a near-field goniophotometer.

A collection of six different types of directional and non-directional integrated LED lamps with three samples of each were used as test devices. It is shown that the main uncertainty comes from the inadequate thermal stabilisation of the LED lamps. With pre-heating relative differences for total luminous flux of ±2,5% were obtained.

Reliable photometric data can be obtained for use in market monitoring to identify probable non-compliance LED lamps and hence as an improved method for selecting LED lamps for accredited verification testing.