LED IT LIGHT – 60x60cm LED panel 40Watt – cold white

Nov 08

LED IT LIGHT – 60x60cm LED panel 40Watt – cold white

Posted by Marcel van der Steen in Led lights, Light measurements No Comments»

presents a a led panel with dimensions of 600 x 600 mm and emitting cold white light.

This article shows the measurement results. Many parameters are also found in the Eulumdat file.

See this overview for a comparison with other light bulbs.

Summary measurement data

parameter	meas. result	remark
Color temperature	5511 K	Cold white
Luminous intensity I_v	910 Cd	Measured straight underneath the lamp.
Illuminance modulation index	27 %	Measured straight underneath the lamp. Is a measure for the amount of flickering.
Beam angle	119 deg	119º for all the C0-C180-plane (cutting the lamp in two (not diagonally)) and 119º for the C90-C270 plane, which is pendendicular to the C0-C180 plane.
Power P	40.8 W
Power Factor	0.88	For every 1 kWh net power consumed, there has been 0.5 kVAhr for reactive power.
THD	28 %	Total Harmonic Distortion
Luminous flux	2804 Lm
Luminous efficacy	69 Lm/W
EU-label classification	A	The energy class, from A (more efficient) to G (least efficient).
CRI_Ra	62	Color Rendering Index.
Coordinates chromaticity diagram	x=0.3325 and y=0.3613
Fitting	230V	This lamp is connected directly to the 230 V grid voltage.
PAR-value	7.2 μMol/s/m²	The number of photons seen by an average plant when it is lit by the light of this light bulb. Value valid at 1 m distance from light bulb.
PAR-photon efficacy	0.5 μMol/s/W_e	The toal emitted number of photons by this light, divided by its consumption in W. It indicates a kind of efficacy in generating photons.
S/P ratio	1.8	This factor indicates the amount of times more efficient the light of this light bulb is perceived under scotopic circumstances (low environmental light level).
L x W x H external dimensions	596 x 596 x 50 mm	External dimensions of the lamp.
L x W luminous area	552 x 552 mm	Dimensions of the luminous area (used in Eulumdat file). This is the surface of the matte cover.
General remarks		The ambient temperature during the whole set of measurements was 23.5 – 25.3 deg C. The temperature of the housing gets about 5 degrees hotter than ambient temperature. The power supply at the back side gets hotter. Warm up effect: during the warm up time the illuminance and consumed power vary less than 5 %. Voltage dependency: the power consumption and illuminance vary insignificantly, when the power voltage varies between 200-250 V. At the end of the article an additional photo.
Measurement report (PDF)	tbc
Eulumdat file		Right click on icon and save the file.

Overview table

The overview table is explained on the OliNo website.

Please note that this overview table makes use of calculations, use this data with care as explained on the OliNo site. E (lux) values are not accurate, when within 5 x 843 mm (diagonal measure) ≈ 4300 mm. Within this distance from the lamp, the measured lux values willl be less than the computed values in this overview as the measurements are then within the near field of the lamp.

EU Energy label classfication

With the measurement results of the luminous flux and the consumed power the classification on energy of this lamp is calculated. This information is requested in the EU for certain household lamps, see also the OliNo site that explains for which lamps it is requested, how the label looks like and what information it needs to contain.

Herewith the labels for this lamp in color and black and white.

EU energy label of this lamp

Label in black and white.

Eulumdat light diagram

This light diagram below comes from the program Qlumedit, that extracts these diagrams from an Eulumdat file. It is explained on the OliNo site.

The light diagram giving the radiation pattern.

It indicates the luminous intensity around the light bulb. The C0-C180 plane is along the width direction of the lamp) and is the same as with the C90-C270 plane (along the length direction of the lamp).

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 average of the light output of the light diagram given earlier. Also, in this graph the luminous intensity is given in Cd.

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. There normally are differences in illuminance values for different turn angles. However for further calculations the averaged values will be used.

When using the average values per inclination angle, the beam angle can be computed, being 119º for the C0-C180 and 119º for the C90-C270 plane.

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 2804 Lm.

Luminous efficacy

The luminous flux being 2804 Lm, and the power of the light bulb being 40.8 W, yields a luminous efficacy of 69 Lm/W.

Electrical properties

A power factor of 0.88 means that for every 1 kWh net power consumed, a reactive component of 0.5 kVAr was needed.

Lamp voltage	230 VAC
Lamp current	202 mA
Power P	40.8 W
Apparent power S	46.4 VA
Power factor	0.88

Of this light bulb the voltage across ad the resulting current through it are measured and graphed. See the OliNo site how this is obtained.

Voltage across and current through the lightbulb

This waveforms have been checked on requirements posed by the norm IEC 61000-3-2:2006 (including up to A2:2009). See also the explanation on the OliNo website.

Harmonics in in the current waveform and checked against IEC61000-3-2:2006 and A2:2009

There are limits for the harmonics for lighting equipment > 25 W and these are just not fulfilled.

Note: the used voltage has more harmonic content than allowed for a correct determination according to the norms mentioned. When applying a clean enough voltage (meaning a low harmonic content as described) it may well be possible that the current does fulfill the requirements. Therefore with this measurement it cannot be stated that the lamp’s current does not fulfill the requirement according to the norm.

Harmonics in in the voltage waveform and checked against IEC61000-3-2:2006 and A2:2009

The Total Harmonic Distortion of the current is computed as 28 %.

Temperature measurements lamp

The plate viewed from the back

The emissivity is the same as that of the masking tape, here taken as 0.95.

The power supply unit at the back side of the panel is the hottest part

The front of the led panel

The emissivity of the front part of the lamp also is equal to that of the masking tape.

Two binding bands are visible which were used to fix the lamp. In the determination of the luminous flux and the determination of the radiation diagram the correction for this covering effect of the two bands has been done. As a result the luminous flux and radiation diagram and intensity values are correct.

status lamp	> 2 hours on
ambient temperature	24.5 deg C
reflected background temperature	24.5 deg C
camera	Flir T335
emissivity	0.95⁽¹⁾
measurement distance	1 m
IFOV_geometric	0.136 mm per 0.1 m distance
NETD (thermal sensitivity)	50 mK

⁽¹⁾ See the text for explanation.

Color temperature and Spectral power distribution

The spectral power distribution of this light bulb, energies on y-axis valid at 1 m distance.

The measured color temperature is about 5500 K which is cold 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 measurement of CCT is measured for inclination angles up to 80º. Beyond this angle the illuminance is very low (< 5 lux).

The beam angle is 119º, meaning a 59.5º inclination angle. In this area most of the light is present. The variation in correlated color temperature in this area is < 1 %.

PAR value and PAR spectrum

To make a statement how well the light of this light bulb is for growing plants, the PAR-area needs to be determined. See the OliNo website how this all is determined and the explanation of the graph.

The photon spectrum, then the sensitivity curve and as result the final PAR spectrum of the light of this light bulb

parameter	value	unit
PAR-number	7.2	μMol/s/m²
PAR-photon current	22.0	μMol/s
PAR-photon efficacy	0.5	μMol/s/W

The PAR efficiency is 63 % (valid for the PAR wave length range of 400 – 700 nm). So maximally 63 % of the total of photons in the light is effectively used by the average plant (since the plant might not take 100 % of the photons at the frequency where its relative sensitivity is 100 %).

S/P ratio

The S/P ratio and measurement is explained on the OliNo website. Here the results are given.

The power spectrum, sensitivity curves and resulting scotopic and photopic spectra (spectra energy content defined at 1 m distance).

The S/P ratio is 1.8.

More info on S/P ratio can be found on the OliNo website.

Chromaticity diagram

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

The light coming from this lamp is outside the area of class A. This is an area defined for signal lamps, see also the OliNo website.

Its coordinates are x=0.3325 and y=0.3613.

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). Practical information and also some critics about the CRI can be found on the OliNo website.

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 62 is lower than to the value 80 which is considered a minimum value for indoor usage.

Note: the chromaticity difference is 0.0069 indicates the distance to the Planckian Locus. There is no norm yet that states what the max deviation from white light is allowed to be. A reference with signal lights as a reference is given in the chromaticity diagram.

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 light bulb parameters measured: illuminance E_v [lx], 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 illuminance and consumed power vary insignificantly when the voltage is varied.

When the voltage at 230 V varies with + and – 5 V, then the illuminance varies < 0.1 %, so when abrupt voltage changes occur this effect is not visible in the illuminance output.

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], the lamppower P [W] and the luminous efficacy [lm/W].