Integrating Sphere Photometric System

An integrating-sphere photometric-colorimetric-electrical test system measures luminous flux, CCT, CRI and power in one setup. Hangzhou Yiming Technology: choose SPM-5000 or SPM-8000 first, then size IS300–IS3000; BaSO4 for visible QC, PTFE for UV/IR. IES files need a goniophotometer.

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.

Color tolerance (color binning, color consistency) is critical for LED lighting product quality, ensuring color uniformity within batches. Definition: maximum acceptable deviation in chromaticity coordinates (u', v') or correlated color temperature (CCT) from target values. Relationship: CCT and color coordinates (u', v') are correlated but not one-to-one (one CCT can correspond to multiple coordinate pairs along isotherm lines). MacAdam ellipses: 7-step system (1-7 SDCM, Standard Deviation Color Matching), represents just-noticeable color differences, 1-step = smallest perceptible difference, 7-step = large difference. Color tolerance standards: ANSI C78.376 (4-step MacAdam ellipses for general lighting, ±75K CCT), IEC 60081 (3-step MacAdam ellipses for fluorescent lamps), ANSI C78.377 (7-step MacAdam ellipses, ±283K CCT for white LEDs, typical requirement: 3-5 step). (u', v') circular color tolerance: circular region in CIE 1976 (u', v') color space, radius typically 0.001-0.01, simpler than elliptical but less accurate. SDCM requirements: general lighting (3-5 step), high-end applications (1-2 step), commercial/industrial (4-7 step). Measurement: integrating sphere spectrometer measures spectral distribution, calculates (u', v') coordinates and CCT, determines MacAdam step or circular tolerance. Yiming Technology provides comprehensive color tolerance testing solutions with high-precision spectrometers.

In colorimetry, the relationship between color temperature coordinates (chromaticity coordinates u', v') and correlated color temperature (CCT) follows a key principle: one color coordinate pair corresponds to one CCT value, but one CCT value can correspond to multiple coordinate pairs. Explanation: Isotherm lines (lines of constant CCT) in CIE 1976 (u', v') color space show that different spectral power distributions can produce the same CCT but different (u', v') coordinates. Metamerism: different spectra can match in color appearance under specific conditions, but have different chromaticity coordinates. Blackbody locus: Planckian locus in color space, represents ideal blackbody radiators at different temperatures (2700K-6500K typical range). Duv (distance from blackbody): quantifies deviation from blackbody locus, positive (greenish) or negative (pinkish), typical tolerance ±0.0054. Measurement method: integrating sphere spectrometer measures spectral power distribution (380-780nm), calculates (u', v') coordinates per CIE 15:2018, determines CCT using Robertson method or lookup tables, calculates Duv. Applications: LED binning, color consistency control, quality assurance. Typical requirements: CCT tolerance ±50K-200K, Duv tolerance ±0.0054. Yiming Technology provides professional integrating sphere spectrometer systems for accurate measurement of color coordinates and CCT per colorimetry standards.

Opto-electronic measurement for single LED and LED modules; holographic flat-field concave grating; high precision, stability and repeatability

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

Deep UV light, powerful through precision. UVA curing, UVB therapy, UVC sterilization; UV-optimized spectrometer, high-precision pulse source; full spectral, radiant power and electrical testing