Goniophotometer Selection Guide

A light-distribution curve test system is a goniophotometer bench that exports IES/LDT/GLDF/SPDX. Hangzhou Yiming Technology GMS-5000 supports .ies/.gldf/.ldt/.xml/.spdx for LM-79; GMS-1920/1680 for 8 m/6 m rooms; GMS-1280 box type; GMS-136 for single-LED distribution.

Hangzhou Yiming Technology: LM-79-24 Kelvin four-wire external voltage sensing for SSL. Two-wire internal sampling reads U=Ulamp+I×R (lead drop included), so voltage and power are high and efficacy is low—skewing LM-79 energy-efficiency measurement and light-distribution curve testing. Use GMS-5000, GMS-1920 and SPM-5000 under true lamp-head voltage.

IES LM-79-19 standard (ANSI/IES LM-79-19) is the authoritative standard for electrical and photometric testing of LED luminaires, officially released in May 2019 by ANSI (American National Standards Institute) and IES (Illuminating Engineering Society of North America), replacing LM-79-08. Key requirements: test environment (25℃±1.2℃, humidity 10%-65%, airflow 2m/s), AC power supply accuracy (±0.2% load regulation, 1% reading + 0.1% range), DC power supply accuracy (±0.2% load regulation, 1% voltage/current), power meter (1KHZ-100KHZ sampling, ≤0.6% uncertainty for 5HZ-1KHZ, ≤2% for 1KHZ-100KHZ), spectrometer (380-780nm wavelength range, ≥5nm measurement interval, 5nm wavelength accuracy), photometric probe (f2<2%, f1<3%), goniophotometer test intervals (beam angle ≤20°: 1°/2°/5° intervals; >20°: 2°/5° intervals), and warm-up stability (30min monitoring, 5% stability threshold). Two test methods: integrating sphere with spectrometer (luminous flux, spectral distribution, CCT, CRI) and goniophotometer (light distribution, photometric curves, luminous intensity). Yiming Technology's GMS goniophotometer and SPM5000 integrating sphere spectrometer systems fully comply with IES LM-79-19 requirements.

IES:LM-63-2019 file format (ANSI-approved, *.ies extension) is the standard photometric data format for luminaire testing, widely used in lighting design software. File structure includes: header (IES:LM-63-2019 standard identifier, [TEST] report number, [TESTLAB] laboratory name, [ISSUEDATE] test date/time, [MANUFAC] manufacturer, TILT setting), test parameters (number of light sources, luminous flux in lm, luminous intensity multiplier, vertical/horizontal angle counts, test type Type C, unit meter, luminous surface dimensions width/length/height, ballast factor, output power), angle data (vertical angles: 0°-90° in 1° increments for Type C, typically 91 values; horizontal angles: 0°-360° in 22.5° increments, typically 17 values), and luminous intensity matrix (rows×columns = horizontal angles × vertical angles). Compatible software: Photometric, Dialux, LDT Editor. Applications: photometric curve analysis, 3D light distribution visualization, illuminance calculations, isolux curves. Yiming Technology's GMS goniophotometer system generates IES:LM-63-2019 compliant files with complete photometric curve and light distribution data.

UGR (Unified Glare Rating) is a standardized metric for evaluating discomfort glare in indoor lighting per CIE 117:1995 and EN 12464-1. Definition: UGR quantifies psychological discomfort from glare, calculated using formula involving background luminance, luminaire luminance, solid angle, and position index. UGR scale: 10-30 range, lower values indicate less glare (UGR<19 imperceptible, 19-22 just perceptible, 22-28 acceptable, >28 uncomfortable). UGR table: Matrix showing UGR values for different combinations of room dimensions (length, width, height) and luminaire mounting height, typically 5×5 or 10×10 grid. How UGR tables are obtained: Goniophotometer measures luminous intensity distribution, software calculates UGR using CIE formula for various room configurations, generates UGR table. Reading UGR tables: Rows represent room length/width ratios, columns represent mounting height ratios, intersection values are UGR ratings. Using UGR in design: Select luminaire with appropriate UGR table, match room dimensions to table values, ensure UGR<19 for offices, UGR<22 for general areas, UGR<28 for industrial areas. Standards: CIE 117:1995 (calculation method), EN 12464-1 (lighting requirements, UGR limits), IES LM-83 (UGR calculation). Yiming Technology provides UGR measurement and calculation services using goniophotometer systems.

Complete LED luminaire photometric distribution testing, compliant with GB/T 39394, CIE S 025, IES LM-79 and related standards

Lamp and luminaire opto-electronic measurement system for whole lamps, LED lamps, modules and light strips, compliant with LM-79 and related standards

VAD fire alarm effective intensity and light distribution test system; GMS-2020A for VAD photometric performance; C-x-y/W-x-y coverage volume measurement; compliant with GB26851, ANSI/UL1638-2023, AS-ISO-7240.23-2014, BS EN 54-23-2010