Metro station LED Linear Fixture LM70 test

metro station batten lights

The performance of LED linear fixtures in metro stations is crucial to ensure efficient lighting and maintain a safe environment for passengers. One essential test that is conducted to evaluate their longevity is the LM70 testing. In this article, we will dive into the details of how metro station LED linear fixtures undergo LM70 testing to determine their performance over time.

metro station batten lights

The LM70 testing method focuses on assessing the lumen maintenance of LED fixtures after a specific period. Specifically, it measures the light output degradation of the fixtures. The test duration is often carried out for a minimum of 6,000 hours, although longer durations can provide more accurate results.


Understanding LM70 Testing: A Foundation of Longevity Evaluation

LM-70 testing is a standardized procedure utilized in the lighting sector to evaluate the lumen retention of LED (light-emitting diode) products over time. The “LM” denotes “lumen maintenance,” while the number “70” signifies the percentage of initial light output expected to be sustained by the LED product after a specified duration, typically ranging from 6,000 to 50,000 hours.

1. Unveiling LM70: Tracing Lumens’ Path

The LM70 test serves as a fundamental aspect in assessing the endurance of LED luminaires, with a specific focus on lumen retention. Established by the Illuminating Engineering Society (IES), this test quantifies an LED fixture’s capacity to uphold its light emission over time. By gauging the decline in lumens following 6,000 hours of uninterrupted operation, LM70 provides a tangible measure for forecasting long-term efficacy.

2. Setting the Stage: Priming for Success

Prior to test commencement, meticulous groundwork is imperative. This entails installing the LED linear fixtures in a controlled environment mirroring real-world metro station conditions, inclusive of temperature fluctuations and characteristic humidity levels of underground transit systems. Ensuring accurate wiring and alignment lays the foundation for precise test outcomes.

3. Establishing Baseline: Initiating Illumination

The LM70 testing journey commences with benchmark establishment. An initial lumen output assessment is conducted using a calibrated lux meter to capture the LED fixtures’ full potential before temporal and usage impacts take effect. This foundational data serves as a crucial reference against which all subsequent degradation is measured.

4. Time’s Trial: Ongoing Surveillance
Throughout a duration of at least 6,000 hours, the LED fixtures undergo continuous operation while parameters such as voltage and temperature are vigilantly monitored. Regular interim inspections capture subtle fluctuations in light output, furnishing a comprehensive depiction of the fixtures’ performance trajectory.

5. Quantifying Temporal Impact: Lumen Maintenance Ratio

Upon conclusion of the testing period, the calculus of longevity comes into play. By dividing the final lumen output by the initial measurement and multiplying by 100, the percentage of retained light output—lumen maintenance—is ascertained. This metric transcends mere numerical values; it epitomizes the fixture’s resilience.

6. Unraveling Findings: Interpretations and Implications

Deciphering the outcomes of LM70 testing holds paramount importance in decision-making processes. Elevated lumen maintenance percentages denote robust endurance, aligning with the stringent criteria of metro stations. This analysis lays the groundwork for approving LED fixtures for deployment, ensuring compliance with safety, efficiency, and longevity benchmarks.

7. Chronicling the Voyage: Concluding Documentation

No assessment is complete sans documentation. A comprehensive report encapsulating the entirety of the testing journey, from initial assessments to final calculations, emerges as a vital resource for future endeavors. This dossier serves as a guide for maintenance strategies, replacement timetables, and potential enhancements.

LM70 testing on metro station LED linear fixtures is a crucial process as it allows stakeholders to make informed decisions regarding the performance and longevity of the lighting system. By ensuring consistent lighting levels over time, not only do LED fixtures provide a safe environment for passengers, but they also contribute to energy savings and reduced maintenance costs.


Performing LM70 testing on LED linear fixtures in metro stations allows for an accurate evaluation of their lumen maintenance. By following the steps outlined in this article, stakeholders can assess the performance and longevity of these fixtures, leading to informed decisions regarding their installation and maintenance.



What is LM70’s significance in LED lighting assessments?

In LED lighting assessments, LM-70 represents “Lumen Maintenance Testing at Elevated Temperatures.” This is a standardized procedure developed by the Illuminating Engineering Society of North America (IESNA) to assess the lumen maintenance of LED (light-emitting diode) products over time. The abbreviation “LM” denotes “lumen maintenance,” which refers to an LED product’s ability to sustain its initial light output throughout its operational life. The numerical designation “70” indicates the percentage of initial light output that the LED product is projected to maintain after a specified duration, typically ranging from 6,000 to 50,000 hours.

Why is LM70 testing specifically significant for LED linear fixtures within subway stations?

In subway stations, consistent and dependable lighting is crucial for passenger safety and operational efficiency. LM70 testing guarantees that LED linear fixtures can uphold adequate light output over time, lessening the necessity for frequent maintenance and replacements.

How does the testing environment influence LM70 test outcomes for LED fixtures?

The testing environment must replicate real-world conditions to ensure precise outcomes. Variables such as temperature, humidity, and airflow are regulated to mimic those encountered in subway stations, as deviations can affect the durability and performance of LED fixtures.

What occurs if an LED linear fixture does not pass the LM70 test?

Falling short of LM70 standards implies that the fixture might not deliver sufficient light output throughout its anticipated lifespan. Such fixtures would generally not be recommended for installation in critical zones like subway stations, and manufacturers might need to revise the product design or materials.

Can LM70 test results facilitate comparison between different models of LED linear fixtures?

Certainly, LM70 results serve as a standardized benchmark, enabling direct comparison of the longevity and performance of different LED fixtures. This aids decision-makers in selecting the most appropriate lighting solution for their specific requirements.

Share this post