IEC 60068 2 40 Thermal Humidity Combined Cycle Testing of Luminaires

The International Electrotechnical Commission (IEC) standard IEC 60068-2-40 defines the procedure for conducting thermal and humidity combined cycle testing, which is crucial for ensuring that luminaires meet stringent environmental requirements. This test simulates real-world conditions to evaluate how a luminaire performs under extreme temperature and humidity variations.

The purpose of IEC 60068-2-40 testing is to assess the durability, reliability, and performance of luminaires in challenging ambient conditions. The test involves exposing specimens to cycles of temperature changes (typically between -25°C and +70°C) and relative humidity levels that range from 10% RH to 93% RH. These environmental stresses are designed to mimic the operational environment that a luminaire might encounter during its lifetime.

During testing, specimens undergo multiple cycles of temperature and humidity changes over an extended period. The test cycle may include up to 50 full cycles, each consisting of a heating phase followed by a cooling phase and a final holding phase under high humidity conditions. This rigorous process is intended to stress the luminaire beyond typical operational conditions to reveal any potential weaknesses or defects.

The testing procedure aims to ensure that luminaires not only withstand these harsh environmental conditions but also continue to function correctly after exposure. Compliance with IEC 60068-2-40 standards is essential for manufacturers and distributors of luminaires, as it guarantees the quality and reliability of their products in a variety of environments.

Proper specimen preparation is critical before initiating testing. This includes cleaning the luminaire to remove any contaminants that could affect test results. The luminaire must also be securely mounted on a suitable rack or stand to ensure consistent positioning during each cycle. Calibration of all measurement instruments and sensors used in monitoring temperature, humidity, and other parameters is crucial for accurate data collection.

The testing apparatus required includes environmental chambers capable of maintaining precise control over temperature and humidity levels, along with high-precision thermocouples or resistance temperature detectors (RTDs) to measure these parameters accurately. Humidity sensors ensure that relative humidity levels are maintained within specified tolerances throughout the test cycles.

After completing all cycles, the luminaire is inspected for any signs of damage or malfunction. Key performance indicators include checking the integrity of the luminaire’s structure, verifying proper operation of its lighting components, and assessing changes in luminous flux due to thermal cycling. Compliance with IEC 60068-2-40 standards ensures that a luminaire can withstand the rigors of various environments without compromising its performance or safety.

Real-world applications for this testing are widespread across industries, including automotive, aviation, and industrial manufacturing, where luminaires must operate in harsh environmental conditions. By adhering to IEC 60068-2-40 standards, manufacturers can ensure that their products meet the highest quality and reliability benchmarks.

Automotive lighting systems
Aircraft interior and exterior lighting
Indoor and outdoor industrial lighting fixtures
Marine and offshore equipment luminaires

Frequently Asked Questions

What is the purpose of IEC 60068-2-40 testing?

The primary purpose of this test is to evaluate how luminaires perform under extreme temperature and humidity conditions. It ensures that the luminaire can withstand harsh environmental conditions without compromising its performance or safety.

What kind of specimens are tested?

Specimens for IEC 60068-2-40 testing include luminaires such as lamps, lighting fixtures, and other similar devices. The test is designed to simulate real-world conditions that the luminaire might encounter during its operational life.

How many cycles are typically performed in this test?

The test usually involves up to 50 full cycles, each consisting of a heating phase followed by a cooling phase and a final holding phase under high humidity conditions. This rigorous process is intended to stress the luminaire beyond typical operational conditions.

What equipment is used for IEC 60068-2-40 testing?

The testing apparatus includes environmental chambers capable of maintaining precise control over temperature and humidity levels, along with high-precision thermocouples or RTDs to measure these parameters accurately. Humidity sensors ensure that relative humidity levels are maintained within specified tolerances throughout the test cycles.

What are the key performance indicators (KPIs) for IEC 60068-2-40 testing?

Key KPIs include checking the integrity of the luminaire’s structure, verifying proper operation of its lighting components, and assessing changes in luminous flux due to thermal cycling. Compliance with these standards ensures that a luminaire can withstand harsh environmental conditions without compromising its performance or safety.

Which industries benefit from this testing?

Industries such as automotive, aviation, and industrial manufacturing benefit greatly from IEC 60068-2-40 testing. These sectors require luminaires that can operate reliably in harsh environments.

How long does the test typically take?

The duration of IEC 60068-2-40 testing varies depending on the number of cycles and the specific conditions set for each cycle. Typically, it can last several days to weeks, with some tests extending over multiple weeks.

What standards does this test comply with?

This testing complies with IEC 60068-2-40, which is part of a larger series of environmental tests for electrical and electronic equipment. Compliance ensures that the luminaire meets international quality and reliability benchmarks.