Sep 13
With the ledlamps becoming more and more powerful and given that the blue content of the light from leds in increasing as well, there is a growing concern for blue light hazard.
The IEC 62471:2006 norm explains about how to measure Blue Light Hazard, tha could lead to photoretenitis. This norm has an update in 2008. That update refers to the European Directive 2006/25/EC that contains the ELs. This article explains the way OliNo deals with this norm to measure the blue light hazard (only as an indication!) of the lamps it measures.
Update 28 April 2012: the dimensions of the brightest part of the illuminated part are taken for the calculation (of interest only in non-homogeneous sources).
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Aug 07
This article explains a bit about the biological effects of light on human beings. It appears that next to rod and cones there are other cells sensitive to a certain part of the light spectrum and that influences our daily rhythm (circadian cycle); this is the cycle of sleep and being awake, where a hormone like melatonin plays an important role.
The spectrum of the light enables to compute the biological effect that it can provoke, amongst others in (1) the suppression of melatonin in the night and in (2) shifting the circadian phase. I used the vornorm DIN V 5031-100:2009-06 as the basis of the computation of several interesing parameters coming from the light spectrum.
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Oct 31
When OliNo measures lamps working on 12 V DC and these lamps are dimmable, then it as a 12 V DC dimmer available to use.
This dimmer is put between the 12 V DC power supply output and the lamp itself.
It appears that this dimmer uses a pulse width modulation (PWM) to switch the voltage to the lamp between a high level and a low level; this at a speed invisible to the human eye. It is a very efficient way to adjust the average level of the voltage that is output to the lamp.
This article gives a number of measurements on the output of the dimmer to show what the dimmer does with the voltage to the lamp.
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Oct 12
On 27 January 1998 the commission issued a directive that requires energy labels for household lamps.
In this article the main items from the directive are mentioned and the energy label itself is shown. OliNo will add these into the new lamp measurement articles.
On request this label can be added to already existing articles at a small cost.
Update Nov 9th 2010: on request a graph is added that indicates the performance of the lamp in a Lumen-Watt field. This is a visual indication of in what classification the lamp falls and how well within that classification it is positioned.
Sep 13
OliNo executes endurance tests on (led)lamps. This article explaines what the data that is obtained when doing endurance tests on (led)lamps. An ASSIST publication was used as the basis for the derivation of the results of the measurements.
First the test setup is explained and then the measurements done and extracted.
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Jun 19
When OliNo receives lamps that are dimmable then OliNo has a few dimmers to choose from. Dimmers that are connected between the grid voltage and the lamp have two main principles of operation: phase Wanneer OliNo lampen te meten krijgt die dimbaar zijn, dan heeft OliNo een paar dimmers waaruit ze kan kiezen. De dimmers die rechtstreeks tussen de netspanning en de lamp aangesloten worden kennen een tweetal dim-pincipes: forward phase-cut and reverse phase-cut. Some of it has been explained in an explanation article on this site.
In this article the available dimmers are used for different types of lamps. The current and voltage are measured after the dimmer, so the voltage across the lamp and the current through it.
It will become clear that there are different types of dimmers and lamps react differently. We will look at the voltage and current waveforms to see the differences. The article explains whether the lamp tested was well dimmable with a certain dimmer type or not.
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Apr 26
In almost all lamp measurement articles one can find the measured value for Power Factor. In this article I explain more about it.
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Apr 24
Dimmers are used in many places, to gerenate the requested atmosphere. And one can believe that dimming also saves on consumed power, which is true, but how much?
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Apr 12
Lamps flicker when they are on. Well, most of them do. And with flickering I mean to say they vary in illuminance. There were messages in the media about (led)lams that flicker so much that people got a headache because of it when working in that light..
OliNo has a way to measure the variations in illuminance and attribute to it a number; a so called illuminance modulation index. This article explains how is measured and gives a number of examples.
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Mar 06
What is white light? In the OliNo lamp measurement articles a chromaticity diagram is given and the color point of the light of the tested lamp is indicated. The chromaticity diagram contains all possible colors, and which are white?
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With the ledlamps becoming more and more powerful and given that the blue content of the light from leds in increasing as well, there is a growing concern for blue light hazard.
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