Methods for decreasing uncertainties in LED photometry

Timo Dönsberg, Tomi Pulli, Meelis Sildoja, Tuomas Poikonen, Hans Baumgartner, Farshid Manoocheri, Petri Kärhä, Erkki Ikonen

Research output: Chapter in Book/Report/Conference proceedingConference article in proceedingsScientific

1 Citation (Scopus)

Abstract

Even though energy-efficient and sustainable solutions, such as light emitting diodes (LEDs), have become popular in general lighting, mainly incandescent lamps are used as measurement standards in photometry. Optical properties of the LED lamps together with the often unstable built-in power converters bring challenges to NMIs and testing laboratories. Due to the narrow and complicated spectra of the LED lamps, the uncertainties of traditional photometers calibrated by incandescent lamps tend to increase when LED lamps are measured. Switching from an incandescent lamp to an LED-based calibration source would decrease the uncertainty related to the spectral mismatch correction. LED-based photometric standard lamps would also have other benefits, such as long lifetime and good temporal stability. Moreover, as spectra of white LED lamps are limited to the visible wavelength range, a novel method for illuminance measurements based on the Predictable Quantum Efficient Detector (PQED) can be used to characterize these standard lamps with luminous flux uncertainties significantly below 1 % (k = 2) at NMIs. The method eliminates the need of photometric filters in realization of the illuminance unit. Instead, the photometric weighting is carried out numerically using a separately measured relative spectrum of the source. Well characterized LED-based calibration lamps, together with improved electrical power measurement, would reduce measurement uncertainties of illuminance, luminous intensity, luminous flux and luminous efficacy measurements of LED lamps at NMIs and testing laboratories. This would have a high impact on the development of energy-efficient LED lamps and on the assessment of the energy saving potential of solid state lighting. It is also shown, that recent advances in illuminance and electrical power measurement will enable luminous efficacy measurements of LED lamps with uncertainty well below the present state-of-the-art level of about 1 % (k = 2).
Original languageEnglish
Title of host publicationCIM2015
Subtitle of host publication17th International Congress of Metrology
EditorsBernard Larquier
PublisherEDP Sciences
Number of pages6
DOIs
Publication statusPublished - 2015
MoE publication typeNot Eligible
Event17th International Congress of Metrology, CIM 2015 - Paris, France
Duration: 21 Sep 201524 Sep 2015

Conference

Conference17th International Congress of Metrology, CIM 2015
Abbreviated titleCIM 2015
CountryFrance
CityParis
Period21/09/1524/09/15

Fingerprint

luminaires
photometry
light emitting diodes
illuminance
illuminating
power converters
luminous intensity
photometers
potential energy
solid state
filters
optical properties
life (durability)

Keywords

  • LED
  • LED photometry

Cite this

Dönsberg, T., Pulli, T., Sildoja, M., Poikonen, T., Baumgartner, H., Manoocheri, F., ... Ikonen, E. (2015). Methods for decreasing uncertainties in LED photometry. In B. Larquier (Ed.), CIM2015: 17th International Congress of Metrology [11001] EDP Sciences. https://doi.org/10.1051/metrology/20150011001
Dönsberg, Timo ; Pulli, Tomi ; Sildoja, Meelis ; Poikonen, Tuomas ; Baumgartner, Hans ; Manoocheri, Farshid ; Kärhä, Petri ; Ikonen, Erkki. / Methods for decreasing uncertainties in LED photometry. CIM2015: 17th International Congress of Metrology. editor / Bernard Larquier. EDP Sciences, 2015.
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abstract = "Even though energy-efficient and sustainable solutions, such as light emitting diodes (LEDs), have become popular in general lighting, mainly incandescent lamps are used as measurement standards in photometry. Optical properties of the LED lamps together with the often unstable built-in power converters bring challenges to NMIs and testing laboratories. Due to the narrow and complicated spectra of the LED lamps, the uncertainties of traditional photometers calibrated by incandescent lamps tend to increase when LED lamps are measured. Switching from an incandescent lamp to an LED-based calibration source would decrease the uncertainty related to the spectral mismatch correction. LED-based photometric standard lamps would also have other benefits, such as long lifetime and good temporal stability. Moreover, as spectra of white LED lamps are limited to the visible wavelength range, a novel method for illuminance measurements based on the Predictable Quantum Efficient Detector (PQED) can be used to characterize these standard lamps with luminous flux uncertainties significantly below 1 {\%} (k = 2) at NMIs. The method eliminates the need of photometric filters in realization of the illuminance unit. Instead, the photometric weighting is carried out numerically using a separately measured relative spectrum of the source. Well characterized LED-based calibration lamps, together with improved electrical power measurement, would reduce measurement uncertainties of illuminance, luminous intensity, luminous flux and luminous efficacy measurements of LED lamps at NMIs and testing laboratories. This would have a high impact on the development of energy-efficient LED lamps and on the assessment of the energy saving potential of solid state lighting. It is also shown, that recent advances in illuminance and electrical power measurement will enable luminous efficacy measurements of LED lamps with uncertainty well below the present state-of-the-art level of about 1 {\%} (k = 2).",
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Dönsberg, T, Pulli, T, Sildoja, M, Poikonen, T, Baumgartner, H, Manoocheri, F, Kärhä, P & Ikonen, E 2015, Methods for decreasing uncertainties in LED photometry. in B Larquier (ed.), CIM2015: 17th International Congress of Metrology., 11001, EDP Sciences, 17th International Congress of Metrology, CIM 2015, Paris, France, 21/09/15. https://doi.org/10.1051/metrology/20150011001

Methods for decreasing uncertainties in LED photometry. / Dönsberg, Timo; Pulli, Tomi; Sildoja, Meelis; Poikonen, Tuomas; Baumgartner, Hans; Manoocheri, Farshid; Kärhä, Petri; Ikonen, Erkki.

CIM2015: 17th International Congress of Metrology. ed. / Bernard Larquier. EDP Sciences, 2015. 11001.

Research output: Chapter in Book/Report/Conference proceedingConference article in proceedingsScientific

TY - GEN

T1 - Methods for decreasing uncertainties in LED photometry

AU - Dönsberg, Timo

AU - Pulli, Tomi

AU - Sildoja, Meelis

AU - Poikonen, Tuomas

AU - Baumgartner, Hans

AU - Manoocheri, Farshid

AU - Kärhä, Petri

AU - Ikonen, Erkki

PY - 2015

Y1 - 2015

N2 - Even though energy-efficient and sustainable solutions, such as light emitting diodes (LEDs), have become popular in general lighting, mainly incandescent lamps are used as measurement standards in photometry. Optical properties of the LED lamps together with the often unstable built-in power converters bring challenges to NMIs and testing laboratories. Due to the narrow and complicated spectra of the LED lamps, the uncertainties of traditional photometers calibrated by incandescent lamps tend to increase when LED lamps are measured. Switching from an incandescent lamp to an LED-based calibration source would decrease the uncertainty related to the spectral mismatch correction. LED-based photometric standard lamps would also have other benefits, such as long lifetime and good temporal stability. Moreover, as spectra of white LED lamps are limited to the visible wavelength range, a novel method for illuminance measurements based on the Predictable Quantum Efficient Detector (PQED) can be used to characterize these standard lamps with luminous flux uncertainties significantly below 1 % (k = 2) at NMIs. The method eliminates the need of photometric filters in realization of the illuminance unit. Instead, the photometric weighting is carried out numerically using a separately measured relative spectrum of the source. Well characterized LED-based calibration lamps, together with improved electrical power measurement, would reduce measurement uncertainties of illuminance, luminous intensity, luminous flux and luminous efficacy measurements of LED lamps at NMIs and testing laboratories. This would have a high impact on the development of energy-efficient LED lamps and on the assessment of the energy saving potential of solid state lighting. It is also shown, that recent advances in illuminance and electrical power measurement will enable luminous efficacy measurements of LED lamps with uncertainty well below the present state-of-the-art level of about 1 % (k = 2).

AB - Even though energy-efficient and sustainable solutions, such as light emitting diodes (LEDs), have become popular in general lighting, mainly incandescent lamps are used as measurement standards in photometry. Optical properties of the LED lamps together with the often unstable built-in power converters bring challenges to NMIs and testing laboratories. Due to the narrow and complicated spectra of the LED lamps, the uncertainties of traditional photometers calibrated by incandescent lamps tend to increase when LED lamps are measured. Switching from an incandescent lamp to an LED-based calibration source would decrease the uncertainty related to the spectral mismatch correction. LED-based photometric standard lamps would also have other benefits, such as long lifetime and good temporal stability. Moreover, as spectra of white LED lamps are limited to the visible wavelength range, a novel method for illuminance measurements based on the Predictable Quantum Efficient Detector (PQED) can be used to characterize these standard lamps with luminous flux uncertainties significantly below 1 % (k = 2) at NMIs. The method eliminates the need of photometric filters in realization of the illuminance unit. Instead, the photometric weighting is carried out numerically using a separately measured relative spectrum of the source. Well characterized LED-based calibration lamps, together with improved electrical power measurement, would reduce measurement uncertainties of illuminance, luminous intensity, luminous flux and luminous efficacy measurements of LED lamps at NMIs and testing laboratories. This would have a high impact on the development of energy-efficient LED lamps and on the assessment of the energy saving potential of solid state lighting. It is also shown, that recent advances in illuminance and electrical power measurement will enable luminous efficacy measurements of LED lamps with uncertainty well below the present state-of-the-art level of about 1 % (k = 2).

KW - LED

KW - LED photometry

U2 - 10.1051/metrology/20150011001

DO - 10.1051/metrology/20150011001

M3 - Conference article in proceedings

BT - CIM2015

A2 - Larquier, Bernard

PB - EDP Sciences

ER -

Dönsberg T, Pulli T, Sildoja M, Poikonen T, Baumgartner H, Manoocheri F et al. Methods for decreasing uncertainties in LED photometry. In Larquier B, editor, CIM2015: 17th International Congress of Metrology. EDP Sciences. 2015. 11001 https://doi.org/10.1051/metrology/20150011001