Uncertainty Estimation in Luminous Flux Measured with Goniophotometers using Monte Carlo Method

When it is difficult to apply the methodology established in the GUM to calculate uncertainty in a measurement, the Monte Carlo method can be used to find an estimate of uncertainty. In this work, the Monte Carlo methodology was applied to find the uncertainty in luminous flux, when it is measured by means of a far-field goniophotometer. The methodology was applied on three light intensity matrices from three LED sources. The maximum uncertainty found is 1.2 % with a confidence level of approximately 95.5 %. By means of mathematical calculation and simulation it was determined that the distance between the light source and the sensor is the parameter that most influences the uncertainty in luminous flux.