LED Lighting Engineer: Analysis Of Lighting Equipment Parameters

- Sep 24, 2018-

When consumers try to compare the brightness and battery life of headlamps of different brands, they use the same system to measure the data, which is convenient for horizontal comparison between different models, so as to make the right purchase choice. Christmas lights


LED lighting engineer

Limitations: it is almost impossible to find a measurement system that reflects all of the important functional characteristics of light output and light duration. Christmas lights

The current system is biased towards luminaires with strong lighting centers without taking into account the overall shape of the light output or the light output outside the center. Christmas lights

Therefore, lamps that project strong and accurate light with weak divergent beams will have a longer and more distant rating than those that both project strong and precise light centers and provide stronger broad beams. Christmas lights


What parameters does the system measure?

The first step in measuring the output of light is to determine the minimum amount of light required for effective activity.

We call this minimum light available. Christmas lights

Light can be defined by the brightness of a full moon on a clear night. Christmas lights

As a basic reference value, we define this illumination as 0.25 Lux(lumens per square meter).


In all battery life and light distance measurements, the baseline is 0.25 Lux illumination at a distance of 2 meters.

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The lighting equipment parameter system USES two key characteristic indexes to evaluate headlamp performance: lighting distance and battery life. Christmas lights


Lighting distance = the maximum distance from the light center that provides 0.25 Lux illumination. Christmas lights


Battery life = 2 m distance measurement, and the lamp provides a battery life of 0.25 Lux single-axis illumination.


Light distance - how to calculate

Distance of light, measured in meters, is the farthest distance from which light can maintain a illumination of 0.25 Lux.

As the battery power is used, the distance from which the light is projected to reach 0.25 Lux will be reduced. Christmas lights

The lighting distance is measured in the following intervals:


T = 0 h initial brightness (recorded within 5 minutes after the luminaire is opened)


T = 0:30 h average amount of light after 30 minutes


T = the amount of light after 10 hours of use all night


T = x h to measure the additional time of the light distance


We provide lighting distance parameters in the following format:


Illumination distance detection process


Five luminaires are samples, each of which is tested with two sets of batteries of the same brand as those configured at the time of sale.

The average of the 10 data collected is the parameter values that we will put on the product packaging specification and website.


To calculate the lighting distance, we used a constant power source with the input voltage and the battery input power to measure the intensity peak of the optical axis or the highlight of the lighting mode at a distance of 2 meters.


For example, 4 AA batteries = 6 volts;

2 AA battery = 3 volts;


The inverse proportion formula is then used to calculate the maximum distance the light source can provide to 0.25 Lux illumination.

Similarly, calculate the distance of light at each time period.


For example:


1. Measure the illuminance peak of the light source at a distance of 2 meters.

(d = 2 m, assuming that the test illumination is 200 Lux)


2. Calculate luminous intensity.

(luminous intensity: 200 Lux x 22m = 800 Candela)


3. Calculate the square root to get the illumination distance.

(reverse calculation: the distance to provide 0.25 Lux illumination is the square root of (800/0.25 Lux) = 56.6m)


Battery life


Battery life, measured in hours, means the battery life measured from a distance of 2 meters, and the lamp provides at least 0.25 Lux single-axis illumination.

Battery life is expressed in hours, rounding by 30 minutes at zero. Christmas lights


Battery life test procedure


Measure the light output at t = 0 h with the same constant voltage source output as the specific battery system of the lamp.

Fix the lamp at a distance of 2 meters from the sensor, reduce the power voltage until the light output at 2 meters is 0.25 Lux illumination.

Test the voltage into the lamp with a multimeter. Christmas lights


To test battery life, first assemble the new battery with the same brand and model as the product. Christmas lights

Turn on the lamp and start time monitoring until the battery voltage drops to the voltage when the illumination output is 0.25lux at the 2 meters above. Christmas lights

If no battery is available, use the Energizer or Duracell alkaline battery, or any other battery recommended in the packaging or product description. Christmas lights

If the lamp has auto extinguishing function, please open it again within one minute after auto shut down. Christmas lights