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TC KLV-T8-120 Led tube

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

kips_120cm_ledtube presents a 120 cm long led tube. It is one of KLV’s test range. The tubes are in a development phase and will be commercialized in future for the Belgium market. Other measurements will follow to further optimize this range.

This led tube has 330 smd leds and emits a 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 6330 K cold white
Luminous intensity Iv 440 Cd Measured straight underneath the lamp
Beam angle 139 deg 139º for the C0-C180 plane (crossing the length direction of the tube), and 110º for C90-C270 plane (length direction of tube).
Power P 18.0 W
Power Factor 0.96 For every 1 kWh net power consumed, there has been 0.3 kVAhr for reactive power.
Luminous flux 1570 Lm
Luminous efficacy 87 Lm/W
CRI_Ra 68 Color Rendering Index.
Coordinates chromaticity diagram x=0.3157 and y=0.3306
Fitting FL-tube It is connected directly to the grid.
PAR-value 3.8 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.
S/P ratio 2.0 This factor indicates the amount of times more efficient the light of this light bulb is perceived under scotopic circumstances (ow environmental light level).
D x L external dimensions 30 x 1198 mm External dimensions of the lamp. Excluding the pins.
L x W luminous area 1140 x 24 mm Dimensions of the luminous area (used in Eulumdat file). This is equal to the surface at the front on which the leds are mounted.
General remarks The ambient temperature during the whole set of measurements was 23-23.5 deg C.  The tube ends are measured on temperature (32 deg C and 42 deg C at the place where the power supply is at).

Warm up effect: during the warm up time the variations stay within 5 % variation.

Voltage dependency: the power consumption and illuminance do not depend significantly on the voltage when it is varied from 200 – 250 V.

Measurement report (PDF) olino-pdf
Eulumdat file olino_eulumdat Right click on icon and save the file.

Overview table

kips_120cm_ii_summary2

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.

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.

kips_120cm_ii_light_diagram

The light diagram giving the radiation pattern.

It indicates the luminous intensity around the light bulb. In the length direction (C90-C270) the beam angle is smaller than in the direction perpendicular on the length direction (C0-C180).

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.

kips_120cm_ii_pp_avg

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.

kips_120cm_ii_ev_dep_kantelhoek

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 110-139º, for the C0-180 plane and the c90-c270 plane respectively.

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 1570 Lm.

Luminous efficacy

The luminous flux being 1570 Lm, and the power of the light bulb being 18.0 W, yields a luminous efficacy of 87 Lm/W.

A power factor of 0.96 means that for every 1 kWh net power consumed, a reactive component of 0.3 kVAr was needed.

Light bulb voltage (used on power supply!) 230 VAC
Light bulb current 81 mA
Power P 18.0 W
Apparent power S 18.7 VA
Power factor 0.96

Of this light bulb the voltage across ad the resulting current through it+its constant current driver power supply are measured and graphed. See the OliNo site how this is obtained.

kips_120cm_ii_u_i_waveforms

Voltage across and current through the lightbulb

The current does quite well resemble a sine. The current phase is leading a little bit the voltage. The result is a nice powerfactor of around 0.95.

Also the power spectrum of the current is determined.

kips_120cm_ii_powerspectrumi_percent

Current power spectrum in % of the first harmonic (50 Hz).

A few higher harmonics that all are much lower than the g first harmonic (50 Hz).

Temperature measurements tube

kips_120cm_ledtube_cool_side

Temperature image of the cold side of the tube end, after warm up period (temperatures stabile)

status lamp > 1 hour in on state
ambient temperature 22.5 graden C
camera Flir B-CAM SD
emissivity 1.00(1)
measurement distance 0.2 m
IFOVgeometric 0.75 mm
NETD (thermal sensitivity) 100 mK

(1) The emissivity is set such that the temperature is as close as possible to the temperature determined with a contact temperature measurement sensor.

The IFOVgeometric = 0.75 mm, being the area that is seen by 1 pixel of the camera, at a measurement distance of 0.2 m. For areas of 3×3 pixels the camera can accurately determine the temperature, so the IFOVmeasurement = 2.25 mm. This is a small area that easily fits at the metal back of this tube, enabling measurement of the back side.

On the other side of the tube it is warmer, indicating the power supply that will be internally.

kips_120cm_ledtube_hot_side

Temperature of the heat sink

emissivity 1.0(1)
measurement distance 0.20 m
IFOVgeometric 0.7 mm

This side measures 42 deg C. It is where the current driver will be.

Color temperature and Spectral power distribution

kips_120cm_ii_powerspectrum_at_1m_distance

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

The measured color temperature is about 6325 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.

kips_120cm_ii_cct_function_of_incl

Color temperature as a function of inclination angle.

The measurement of CCT has been stopped when the inclination angle was 75º as the illuminance value was decreased to very low values there (< 5 lux).

The beam angle is 125º, meaning an inclination angle of max 62.5º. Almost all light falls within this angle. The variation of the color temperature within this angle is about 6 %.

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.

kips_120cm_ii_par_spectra_at_1m_distance

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

The PAR number for this light results in 3.8 μMol/s/m2. This value is valid at 1 m distance from the light bulb and valid roughly inside its beam angle.

The PAR efficiency is 65 % (valid for the PAR wave length range of 400 – 700 nm). So maximally 65 % 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.

kips_120cm_ii_s_and_p_spectra_at_1m_distance
The power spectrum, sensitivity curves and resulting scotopic and photopic spectra (spectra energy content defined at 1 m distance).

The S/P ratio is 2.0.

More info will come in a separate article.

Chromaticity diagram

kips_120cm_ii_chromaticity

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

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

Its coordinates are x=0.3157 and y=0.3306.

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.

kips_120cm_ii_cri

CRI of the light of this lightbulb.

The value of 68 is lower than 80 which is considered a minimum value for indoor usage.

Note: the chromaticity difference is 0.0006 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 light bulb parameters measured: illuminance E_v [lx], the lamppower P [W], the (Correlated) Color Temperature [K] and the luminous efficacy [Lm/W].

kips_120cm_ii_voltagedependency

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

The illuminance and consumed power do not vary significantly 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], color temperature CT or correlated color temperature CCT [K], the lamppower P [W] and the luminous efficacy [lm/W].

kips_120cm_ii_startupeffect

kips_120cm_ii_startupeffect_end

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 warm up time is about 20 minutes. During that time the variation of various parameters stay within the 5 %.

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