Evaluation of expanded uncertainties in luminous intensity and illuminance calibrations

Abstract

Detector-based calibrating methods and expressions for calculation of photometric uncertainties related to uncertainties in the calibrations of luminous intensity of a light source, illuminance responsivity of a photometer head, and calibration factors of an illuminance meter are discussed. These methods permit luminous intensity calibrations of incandescent light sources, luminous responsivity calibrations of photometer heads, and calibration factors of illuminance meters to be carried out with relative expanded uncertainties (with a level of confidence of 95.45%) of 0.4%, 0.4%, and 0.6%, respectively.

Experiment analysis of non-uniformity measurement by array detector scanning system

“…The non-uniformity and uncertainty were calculated by using ( 3), ( 4) and ( 5) [2], [24], [25]. Because this study applied to the same prototype that was used in the experiment, the systemic errors such as error of photo detector, micro-controller, A/D converter, and linear slide based occurring in all experiments could be estimated to be equal.…”

“…A method that used for determining the uncertainty was the statistical analysis of Type-A. "The Type-A standard uncertainty is obtained from a probability density function derived from an observed frequency distribution" [24]. The uncertainty Type-A was suitable for analysis in this study.…”

Measurement of Luminous Intensity Using Filtered Trap Detector

“…Nonuniformity would produce measurement errors when the detector used in different position. The uncertainty due to response nonuniformity depends on the position and size of the beam [14][15] . The measurements were done by using a Heliu m-Neon laser.…”

Construction of Two-Axis Goniophotometer for Measurement of Spatial Distribution of a Light Source and Calculation of Luminous Flux

“…4a and b) and to measure E(θ, ϕ) or I(θ, ϕ). Both lamp holders have height-adjustable mounting fixture and special designed lamp sockets, each of which has an E27 screw-in base with a four-pole configuration providing separate operating current and base voltage sensing wires [17]. The lamp voltage is measured directly between two contacts whereas the lamp current is measured as the voltage across a calibrated standard shunt resistor (SR).…”

“…The distance from the entrance aperture of the photometer head to the center of the goniometer was aligned to 1.32 m by using a calibrated length gauge and verified at least ten different points of the goniometer [17]. At the worst case, the thickness of the gauge mark line, ∆d = 0.4 mm, showing the distance on the gauge was used as the distance setting uncertainty, which corresponds to the photometric uncertainty of 0.06%.…”