Goniophotometer A-α, B-β, C-γ test method introduce and how to choose correct test method

The goniophotometer is an instrument that uses spectrophotometry to perform quantitative and qualitative analysis of substances. It is mainly used for the measurement of the light distribution performance of lamps and light sources, that is, the breadth of light sources in different directions of space, and the distribution of color measurement values. The spectrophotometric law is to determine the absorption of light by measuring the absorbance of the measured substance at a specific wavelength or within a certain wavelength range, and then qualitatively and quantitatively analyze the substance. If you need to test IES files, light intensity distribution and other parameters, it is recommended to use the goniophotometer. With the continuous development of the goniophotometer industry, more and more enterprises and industries have applied goniophotometer, and a large number of enterprises have entered the goniophotometer and developed.

The goniophotometer consists of two parts: goniometer; Photometer (can also be a colorimetric test device). And the role of the goniophotometer:
1. Metering light distribution curve, that is, luminosity distribution
2. Test the color distribution
3. Reverse the total luminous flux of the test fixture
4. Provide standard format files such as IES/LDT for back-end lighting designs

Goniophotometer measurement of lamps and lanterns:
The photometric distribution of lamps and lanterns reflects the spatial luminous characteristics of lamps and lanterns, also known as light intensity distribution curve, which is the core parameter of lamps and lanterns From the photometric distribution data, we can know the light number, efficiency, luminous angle, illumination distribution, glare and other parameters of the lamp Obtaining accurate photometric data of lamps depends on correct testing equipment, methods and environment.

Generally, the light intensity distribution of the light source is measured in a certain number of planes. The choice of the type and number of measurement planes depends on the type of light source The International Commission on illumination defines a for the Goniophotometer measurements A- α, B- β, C- γ Three modes:
Mode 1-A-α: Generally applicable to automotive lamp product
Mode 2-B-β: Generally applicable to floodlight
Mode 3-C-γ: Generally applicable to indoor lighting fixtures and road lighting fixtures

How to choose the right test method?
The three modes can be converted to each other, mode B- β And C- γ Most commonly used However, due to mode B- β During measurement, the working attitude of the lamp will change, which is not applicable to lamps sensitive to temperature and attitude For example, the current LED lamps clearly point out in the North American Lighting Commission Standard led photometric measurement (IESNA LM-79-2008) that only can be used for LED photometric distribution meter measurement C-γ pattern.

Since the goniophotometer is used to measure the light intensity, the current method is to calculate the light intensity through the measurement of illuminance The formula is as follows: i=el2 (I is the light intensity, e is the illumination, l is the test distance) and this formula can be established only when the test distance is far enough (the lamp is regarded as a point light source) Therefore, the measurement distance may be far enough, especially for lamps with large light intensity and narrow beam Generally, for indoor lamps, it is required to reach at least 5 times of the luminous surface of the lamp, and for some projection lamps, it may reach 30m.

In addition, the aging of lamps before the test (such as the stability of fluorescent lamps for 100 hours), the test darkroom, ambient temperature and humidity, power quality, etc. are all parameters that affect the measurement It needs to be controlled and noted in the measurement.

Therefore, Lisun launched mode C- γ 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 measuring distance is from 5m to 30m.

Lisun launched the goniophotometric instrument can do the B-β test with two pillars and the C-γ test with single pillar & multi-function jigs, LSG-1890B/LSG-1800A goniophotometer is automatic goniophotometric instrument for luminous intensity distribution measurements with facility for rotating the light source. The LSG-1890B/LSG-1800A uses a constant temperature detector, Japanese motor and German precision angle coder which keep the test results with high accuracy. It is for industrial laboratory photometric data measurement of all kinds of luminaries such as LED luminaries, HID lamps, fluorescent lamps and so on.

Lisun Instruments Limited was found by LISUN GROUP in 2003. LISUN quality system has been strictly certified by ISO9001:2015. As a CIE Membership, LISUN products are designed based on CIE, IEC and other international or national standards. All products passed CE certificate and authenticated by the third party lab.

Our main products are Goniophotometer, Integrating Sphere, Spectroradiometer, Surge Generator, ESD Simulator Guns, EMI Receiver, EMC Test Equipment, Electrical Safety Tester, Environmental Chamber, Temperature Chamber, Climate Chamber, Thermal Chamber, Salt Spray Test, Dust Test Chamber, Waterproof Test, RoHS Test (EDXRF), Glow Wire Test and Needle Flame Test.

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Tags：LSG-1890B , LSG-6000