Type C goniophotometer and type B goniophotometer test difference and how to choose correct goniophotometer type

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

The goniophotometer can be divided into Type C goniophotometer and type B goniophotometer from the appearance, but the two measurement methods have their own advantages and disadvantages.
I. The test principles of Type C and type B goniophotometer are different:
1. Type C goniophotometer (the lamp to be measured remains lit unchanged, the mirror and probe are in coaxial motion)
The luminaire position is always the same, rotating only the mirror to improve data accuracy during testing.

2. type B goniophotometer (the lamp to be measured rotates horizontally/vertically, and the probe position remains unchanged)
In a specific environment, there are several factors that apply the accuracy of the goniophotometer: scanning resolution, viewing angle range, polarization of the instrument itself, air flow, ambient temperature, etc. The most important of these is the polarization, air flow and temperature of the instrument, because when selecting a two-arm / single-arm horizontal spectrophotometer to measure the lamp, the air flow and temperature changes caused by the movement of the lamp itself will reduce the accuracy of the relevant measurement data; the polarization of the instrument will also affect the test accuracy, but with the development of science and technology, the use of more advanced power devices and control technologies, the impact of polarization has been very limited.

II. The two tests require different site conditions:
1. The accuracy and stability of Type C goniophotometer are better than those of type B goniophotometer. The disadvantage is that the price is relatively high, requiring a larger darkroom size, suitable for government laboratories/testing agencies and large companies.

2. The type B goniophotometer itself is relatively simple in structure, and it is easy to achieve high angular accuracy. Relatively vertical distributed photometer, low requirements for anechoic space, low cost. However, whether it is incandescent lamps, fluorescent lamps, metal halide lamps, or other light sources, the change in the ignition point attitude of the lamp will cause fluctuations in the luminescence of the light source to be measured, which will affect the measurement accuracy. For gas discharge lamps, this effect is very pronounced, usually reaching a level of a few percent, and severe ones exceeding ten percent. For solid light sources, such as LED products, the change in the attitude of the ignition point will not directly affect the light source emission, but the attitude change will affect the heat dissipation of the light source under test, and the heat dissipation is very important for many LED products, so the measurement accuracy of the solid light source will also be affected by the ignition point attitude.

III. The two models are different in system configuration:
1. Type C goniophotometer probe, electrical parameter meter, AC/DC power supply and other training fully meet LM-79-19.
2. Type B goniophotometer system configuration, motor/decoder angle accuracy, angle controller and electrical parameter table, as well as the maximum test size of the lamp to be measured.

According to the above-mentioned Lishan Group launch introduced how to choose the correct goniophotometer type:
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 measuring distance is from 5m to 30m.

LM-79 Moving Detector Goniophotometer (Mirror Type C) AL

LSG-1950 is a CIE A-α goiophotometer. The photometer head keeps static and it faces to the sample under test while the sample is rotating around both horizontal axis and vertical axis. So the luminous intensity and illuminance of the lamp or luminaires can be tested. Fully meet the Final Report PC13050202 Oregon, ECE-R65, FMVSS108, GB13954 and GB 25991 Standard.

LSG-1950 Goniophotometer for Automotive and Signal Lamps

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.

High Precision Rotation Luminaire Goniophotometer LSG 1890B AL

The LSG-1200A compact goniophotometer is used to measure the luminous intensity distribution curve, intensity data, beam angle and other photometric parameters for Chip LED, LED Module, LED Spotlight and all other light which spread angle is no more than 180 degree.

LSG 1200A_ Compact Goniophotometer

LSG-1890BCCD/LSG-1800ACCD goniospectroradiometer is high precision automatic goniophotometric instrument for luminous intensity distribution measurement with facility for rotating the light source. The LSG-1890BCCD/LSG-1800ACCD can do the spatial CCT test and the intensity distribution test. It is for industrial laboratory photometric data measurement of luminaires such as LED luminaires, LED Plant Lighting, HID luminaires, 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.

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