Renewable Energy

Line Lite International BV Sharp Silicon

Posted by Marcel van der Steen in Led lights, Light measurements Add comments

line_lite_sharp_siliconLine Lite International BV offers a 230 V led light that looks like a light spot. It is a replacement for existing light spots with an E27 fitting. Also an Eulumdat file is added in this article.

See this overview for a comparison with other light bulbs.

Summary measurement data

parameter meas. result remark
Color temperature 2772 K Warm white
Luminous intensity Iv 86 Cd
Beam angle 56 deg
Power P 4.2 W
Power Factor 0.59 For every 1 kWh net power consumed, there has been 1.4 kVAhr for reactive power.
Luminous flux 117 lm
Luminous efficacy 28 lm/W
CRI_Ra 73 Color Rendering Index.
Coordinates chromaticity diagram x=0.4573 and y=0.4147
Fitting E27
D x H external dimensions 63 x 107 mm External dimensions of the light bulb.
Diameter luminous area 63 mm Dimensions of the luminous area (used in Eulumdat file). This is the diameter of the bulb.
General remarks The ambient temperature during the whole set of measurements was 24 – 28 deg C.

Warm up effect: the illuminance and consumed power decrease resp. 28 and 12 % during the warm up time.

Voltage dependency: consumed power and illuminance are relatively insensitive to light bulb voltage.

Note: according to the supplier, these light bulbs have the Kema Keur label.

The Eulumdat file can be found via this link.

Measurement report (PDF) olino-pdf

Eulumdat light diagram

An interesting graph is the light diagram, indicating the intensity in the C0-C180 and the C90-C270 plane. This light diagram below comes from the program Qlumedit, that extracts these diagrams from an Eulumdat file.


The light diagram giving the radiation pattern.

It indicates the luminous intensity around the light bulb. This light diagram is symmetrical around the z-axis.

The unit is Cd/1000lm, meaning the intensity in Cd assuming there would be 1000 lumen in the measured light bulb. This enables comparing different types of light bulbs.

Illuminance Ev at 1 m distance, or luminous intensity Iv

Herewith the plot of the averaged luminous intensity Iv as a function of the inclination angle with the light bulb.


The radiation pattern of the light bulb.

This radiation pattern is the same as the one given earlier. This is because in this light bulb’s case, the radiation pattern is symmetric around the z-axis, meaning that the averaged pattern given here is the same as the extraction of the Eulumdat file.

These averaged values are used (later) to compute the lumen output.


Intensity data of every measured turn angle at each inclination angle.

This plot shows per inclination angle the intensity measurement results for each turn angle at that inclination angle. So at 30 degrees inclination angle, all the measurement results of illuminance for all measured turn angles are in the range of 37-56 % of the illuminance value at 0 degrees inclination angle.

When using the average values per inclination angle, the beam angle can be computed, being 56 degrees.

Luminous flux

With the averaged illuminance data at 1 m distance, taken from the graph showing the averaged radiation pattern, it is possible to compute the luminous flux.

The result of this computation for this light spot is a luminous flux of 117 lm.

Luminous efficacy

The luminous flux being 117 lm, and the power of the lightbulb being 4.2 W, yields a luminous efficacy of 28 lm/W.

A power factor of 0.59 means that for every 1 kWh net power consumed, a reactive component of 1.4 kVAr was needed.

Light bulb voltage 230 V
Light bulb current 31 mA
Power P 4.2 W
Apparent power S 7.1 VA
Power factor 0.59

Color temperature and Spectral power distribution


The spectral power distribution of this light bulb.

The measured color temperature is about 2800 K which is warm white.

This color temperature is measured straight underneath the light bulb. Below a graph showing the color temperature for different inclination angles.


Color temperature as a function of inclination angle.

The maximum value of inclination angle is 85 degrees. Beyond that value there is virtually no intensity anymore. The color temperature shows about 3 % deviation.

Chromaticity diagram


The chromaticity space and the position of the lamp’s color coordinates in it.

The light coming from this lamp is very close to the Planckian Locus (the black path in the graph).

Its coordinates are x=0.4573 and y=0.4147.

Color Rendering Index (CRI) or also Ra

Herewith the image showing the CRI as well as how well different colors are represented (rendered). The higher the number, the better the resemblance with the color when a black body radiator would have been used (the sun, or an incandescent lamp).

Each color has an index Rx, and the first 8 indexes (R1 .. R8) are averaged to compute the Ra which is equivalent to the CRI.


CRI of the light of this lightbulb.

The value of 73 is lower than 80 which is considered a minimum value for indoor usage.

Note: the chromaticity difference is 0.0017 indicates the distance to the Planckian Locus. Its value is lower than 0.0054, which means that the calculated CRI result is meaningful.

Voltage dependency

The dependency of a number of lamp parameters on the lamp voltage is determined. For this, the lamp voltage has been varied and its effect on the following lamp parameters measured: illuminance E_v [lx], color temperature CT or correlated color temperature CCT [K], the lamppower P [W] and the luminous efficacy [lm/W].


Lamp voltage dependencies of certain light bulb parameters, where the value at 230 V is taken as 100 %.

The consumed power and the illuminance hardly depend on the light bulb voltage; the max variation in the illuminance being about 5 %. When the voltage around 230 V varies with + and – 5 V, then the illuminance varies with less than + and – 1 %, which is not visible.

Warm up effects

After switch on of a cold lamp, the effect of heating up of the lamp is measured on illuminance E_v [lx], color temperature CT or correlated color temperature CCT [K], the lamppower P [W] and the luminous efficacy [lm/W].



Effect of warming up on different light bulb parameters. At top the 100 % level is put at begin, and at bottom at the end.

The illuminance decreases 28 % and the consumed power decreases 12 % during the warm up period of 45 minutes.

4 Responses to “Line Lite International BV Sharp Silicon”

  1. Jeanne Eisenhut Says:

    Hey Marcel:

    How do you know that 80 is a minimum value for indoor light use? What is your source for that? Also, what is the value of a standard 60 watt bulb by comparison?

  2. mvdsteen Says:

    Hi Jeanne,
    In the Netherlands I have a norm called NEN-EN 12464-1 that describes the minimum CRI value for light used in working environments, where it is defined that this value should be 80.
    When looking on the internet for the USA, I found an interesting document of Energy Star that describes criteria for solid state lighting, and defines a minimum value of 75 (see page 3).
    It is normally said that a CRI >= 80 is good enough, however the CRI value is computed for a set of 8 reference colors. One could optimize the light bulb’s light for these 8 colors and then be very bad at rendering other colors. Therefore the used standard is not perfect, and one could choose more colors and check whether these all are rendered well, which is not done yet.

  3. mvdsteen Says:

    A CRI value of a normal incandescent light bulb, is near to 100. The simple heating up of a wire up to 3000 K generates light with a spectrum that contains a lot of colors. All together they form white light for us human beings. And as it contains a full spectrum (meaning all colors are in there), it is well capable of rendering a lot of colors of any object very well.
    Of every light bulb measurement I give the spectrum. Look above at the image called colorspectrum. The x-axis talks about wavelengths of 380 – 780 nm, which represent all the colors we humans can see. The LED does contain quite some colors, so it will be capable of showing a lot of colors from ojects it lights, well. You can compare this spectrum with a spectrom of a CFL. Then you will see that a CFL spectrum has a lot of peaks, and worse, a lot of empty parts where no light is available. So a product with this color will appear black.
    When I have time, I will present a measurement of a normal halogen light together with its spectrum. Then you can compare also with such a type of light bulb.

  4. Jeanne Eisenhut Says:

    Thank you for your thoughtful explanations. Of course I do look at the spectrum graph in your articles because it’s interesting to note the differences from bulb to bulb. As I’ve said before, your articles are well written and easy to understand but I didn’t know if you were using known standards or if you have to invent your own since this is not a well known area of research.

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