The Importance and Methods of Illumination Distribution Measurement and LED Luminaire Flux Testing

Illumination is one of the most important factors impacting human visual perception. The photometric performance of lighting fixtures and the luminous flux of LED fixtures are vital indicators for assessing the quality and performance of the fixtures. This article explores the importance of  Type C Goniophotometer for photometry of lighting fixtures and luminous flux testing of LED fixtures, as well as briefly introducing common measurement methods.

Lighting plays an important role in people’s daily life and work. Proper illumination distribution can improve the lighting effect and provide a comfortable lighting environment. LED luminaires, as anew type of lighting product, have their light flux as one of the important indicators for evaluating their performance and quality. Therefore, it is particularly important to conduct illumination distribution measurement and LED luminaire flux testing.

Type C Goniophotometer is instruments that allow light sources or detectors to rotate, enabling measurement of the light intensity in any direction. They are typically used for measuring the photometric characteristics of fixtures, but can also calculate the luminous flux for all solid angles from the measured light intensity and sum them up to derive the luminous flux of the tested light source.

I. Importance of Illumination Distribution Measurement

Illumination distribution measurement is a key step in evaluating the lighting effect of luminaires. It can help us understand the brightness distribution, directional characteristics, and color correlation of luminaires. Accurate illumination distribution measurement can ensure that the lighting scene achieves the desired effect, meeting the requirements of comfort and visual needs.

Illumination distribution measurement typically includes measuring the light intensity, illumination distribution, and color correlation. Measuring light intensity can help us understand the brightness level and variations of luminaires. Measuring illumination distribution can demonstrate the light projection range and uniformity of luminaires. Measuring color correlation can evaluate the color rendering and color temperature consistency of luminaires. Through illumination distribution measurement, we can obtain comprehensive information on luminaire performance, thereby selecting suitable luminaires for specific lighting scenes and ensuring the desired lighting effect.

II. Importance of LED Luminaire Flux Testing

The light flux of LED luminaires is an important indicator for measuring their lighting effect and energy efficiency. Light flux determines the brightness level of luminaires and directly affects thequality of the lighting effect. Through LED luminaire flux testing, we can accurately obtain the brightness level of luminaires and determine whether they meet the required illuminance requirements.

In addition, the light flux of LED luminaires can also be used to evaluate their energy efficiency. In general, the higher the light flux, the lower the energy consumption of the luminaire. By comparing the light flux of different LED luminaires, we can select luminaires that provide high brightness while consuming less energy, achieving energy-saving and environmentally-friendly lighting requirements.

Preparation before operating a vertical distributed photometer:

1. Prior to operation, the tester needs to check whether the signal lines, control lines, and power lines between the different components of the vertical distributed photometer system are properly connected.
2. Rotate the key switch on the system rotation cabinet panel, turn on the main power, then press the “Motor” button to turn on the power for the mechanical part, press the “Meter” button to turn on the power for the photometer and angle measuring controller inside the cabinet, and then press the LS2010 power switch to turn on the power for the voltmeter.
3. Observe whether all the testing instruments inside the cabinet are properly connected with the mechanical part. In normal conditions, all the instruments except for the reference signal should display “0”, while the rest should immediately display data. If “0” is displayed, it indicates a failed connection between the testing instruments and the mechanical part. In this case, turn off the power for all the instruments inside the cabinet and then turn them on again.
4. Set the ship-shaped switch on the cabinet panel to the “CF” position.
5. Turn on the power for the computer system and wait for the computer to enter the Windows interface. Double-click onthe software for the vertical distributed photometer system.

III. Methods of Illumination Distribution Measurement and LED Luminaire Flux Testing

1. Methods of Illumination Distribution Measurement
Illumination distribution measurement is typically conducted using photometric instruments, including light intensity meters, goniophotometers, and colorimeters.

– Light intensity meters are used to measure light intensity and obtain brightness values at different spatial positions.
– Goniophotometers can measure the illumination distribution of luminaires and provide light intensity and distribution curves at different angles.
– Colorimeters can measure color correlation of luminaires, including color temperature, color coordinates, and color rendering index.
By using these instruments, we can obtain comprehensive data on the illumination distribution performance of luminaires and determine whether they meet the requirements.

2. Methods of LED Luminaire Flux Testing

LED luminaire flux testing can be conducted using direct measurement or indirect measurement methods.
– Direct measurement involves placing the LED luminaire in a flux testing instrument to obtain the light flux value. Common instruments used are integrating spheres and flux tubes.
– Indirect measurement involves measuring the photometric parameters of the LED luminaire, such as current and voltage, and then calculating the light flux value based on the photometric parameters and the characteristic curves of the LED luminaire. This method is relatively simple but requires knowledge and analysis capability of the characteristic curves of the LED luminaire.

Whether using direct measurement or indirect measurement methods, professional flux testing instruments should be used to ensure the accuracy and reliability of the test results.

In conclusion, illumination distribution measurement and LED luminaire flux testing are essential for evaluating the quality and performance of luminaires. Illumination distribution measurement helps in selecting luminaires suitable for lighting scenes and ensuring the desired lighting effect. LED luminaire flux testing evaluates the lighting effect and energy efficiency of luminaires, allowing for the selection of luminaires with high brightness and low energy consumption to achieve energy-saving and environmentally-friendly lighting goals.

When conducting illumination distribution measurement and LED luminaire flux testing, professional measurement instruments should be used, and the test methods should be strictlyfollowed to obtain accurate and reliable test results. Only through scientific test methods and accurate test data can informed decisions be made regarding luminaire selection and lighting design, providing people with a comfortable and efficient lighting environment.

What is the definition of type C goniophotometer?

LSG-6000 Moving Detector Goniophotometer (Mirror Type C) was manufactured by LISUN completely meets LM-79-19, IES LM-80-08, COMMISSION DELEGATED REGULATION (EU) 2019/2015, CIE-121, CIE S025, SASO 2902, IS16106 and EN13032-1 clause 6.1.1.3 type 4 requirements. LSG-6000 is the latest upgraded product of LSG-5000 and LSG-3000 in compliance with the requirements of the LM-79-19 standard Clause 7.3.1, its an automatic light distribution intensity 3D curve testing system for measuring light. The darkroom can be designed according to the customer’s existing room size.

Tags：LSG-6000