In the LED lighting industry, LM-79 testing is widely recognized as the touchstone of product performance.Whether applying for Energy Star, DLC in the U.S., or entering EU and Australian markets, an IES LM-79 compliant test report is mandatory to prove optical and electrical performance.

This article explains what LM-79 is, the latest LM-79-24 update, why it matters, how to choose a lab, and recommends a top provider:Guangdong Meide Certification & Testing Technology Co., Ltd.

1. What Is LM-79 Testing?

ANSI/IES LM-79Electrical and Photometric Measurements of Solid-State Lighting Productsis the industry gold standard for testing LED luminaires.

1.1 Core Concept: Absolute Photometry

LM-79 tests the complete luminaire (LED + driver + heat sink) as a single system,reflecting real‑world performance.

1.2 Key Test Equipment

• Integrating Sphere SystemMeasures: total luminous flux, efficacy, CCT, CRI, spectrum, power, PF.Suitable for small- and medium-sized lamps.

• GoniophotometerMeasures: luminous intensity distribution, light distribution curve, beam angle, total flux (absolute).Ideal for high-power and asymmetric luminaires (street lights, floodlights).

1.3 Full Test Parameters

Optical:Luminous flux (lm), efficacy (lm/W), intensity distribution, chromaticity coordinates, CCT, CRI (Ra/R9), radiant flux.

Electrical:Voltage, current, active power, power factor, THD, frequency.

2. Major Update: ANSI/IES LM-79-24 (2025)

In early 2025, LM-79-24 replaced LM-79-19.

Key Changes:

• New definition of beam center
• Test circuit capacitance adjusted from ≤1.5 nF to ≤2.0 nF
• Harmonic measurement simplified: 2nd to 50th order
• Added flux integration principles for light distribution

Impact:

New standard will gradually apply to global energy certifications.Meide Testing has fully adopted LM-79-24 to ensure compliance.

3. Why LM-79 Testing Is Critical

3.1 Mandatory for Global Energy Certifications

Required for:

• USA: Energy Star, DLC, DOE, CEC
• Australia: VEET, IPART, GEMS
• Brazil, Malaysia, Mexico, and more

3.2 R&D Optimization Tool

Pinpoint issues:

• Low efficacy → driver, chip, or lens
• CCT shift → phosphor or LED binning
• Poor uniformity → reflector or lens design

3.3 Essential for Bidding & Projects

Official LM-79 data strongly supports municipal and commercial tenders.

3.4 Build Customer Trust

Third-party test report = reliable quality endorsement.

4. How to Choose a Professional LM-79 Lab

• Authoritative Accreditation: CNAS, CMA, NVLAP
• High-Precision Equipment: integrating sphere & goniophotometer
• Strict Environment Control: 25°C ±1°C, air speed ≤0.2 m/s
• Experienced Engineering Team
• One-Stop Certification Service (LM-79 → DLC / Energy Star)

5. Recommended LM-79 Lab:

Guangdong Meide Certification & Testing Technology Co., Ltd.

A leading lighting test arm of GTG Group, Meide Testing stands out in LM-79.

5.1 Top-Tier Hardware

• High-precision Everfine integrating spheres (2m / 0.5m)
• Advanced goniophotometer for accurate light distribution
• Special tests: rise time, flicker measurement

5.2 Strict Test Environment

• Temperature: 25°C ±1.2°C
• Humidity: 10%–65%
• Air speed: ≤0.2 m/s
• Full stabilization before test (30 min–2 hours)

5.3 Senior Technical Team (12+ Years)

• R&D pre-assessment
• Data analysis & optimization suggestions
• Expert in LM-79, LM-80, TM-21

5.4 One-Stop Global Certification

LM-79 → LM-80 → TM-21 → DLC / Energy Star / CE / CCCFull service in one partner.

Conclusion

LM-79 is more than compliance — it’s market competitiveness.A precise, authoritative report speeds up certification, improves R&D, wins projects, and builds trust.

For professional LM-79 testing to the latest LM-79-24 standard,Guangdong Meide Certification & Testing Technology Co., Ltd. is your best choice.