Basic Theories About Goniophotometer Part1: Luminous Intensity Measurement

Main functions and basic principle of goniophotometer

1. Goniophotometer for luminous intensity measurement.

A goniophotometer is a photometer for the measurement of the angular dependence of a photometric quantity, that is why “goniophotometer” has been named. It is applied widely t measure te luminous intensity distribution, luminous flux and efficiency of lamps and luminaries. Take the photometric center of the light source as the center, rotate the photometer head around the center in distance. The stability of the tested lamps or luminaires, the measuring distance  angle and illuminance are the four major factors for the luminous intensity distribution measurement, that is, to measure the luminous intensity distribution accurately, it is particularly important to ensure that the test light source always working in a stable state, to measure at an appropriate distance, to measure the relative rotation angle between the tested lamps or luminaires and the photometer head accurately and to measure the illuminance precisely.

Luminous intensity can be measured via a measurement of the illuminance and the distance between the tested light source and the photometer detector according t the photometric distance law:

I(γ)=d*d*E(γ)

In this equation, I(γ) is the luminous intensity of the lamp or luminarie in a certain direction, (unit: cd); d is the measuring distance (unit: m); and γ is the spatial angle (unit: degree).

About Lisun Group:

Lead in CFL and LED Tester. Click to our product lists:

Goniophotometer
Spectroradiometer
Integrating Sphere
Colorimeter and Photometer
LED Test Instruments
CFL Testing Instruments
EMC testing
Electronic Ballast Tester
Equipments for Testing Electronic components
Electrical Safety Tester
Environmental Chamber
AC and DC power supply
Spectrophotometer

Tags：Goniophotometer , Luminous Intensity Measurement