Damp Heat Tester? Working Principle & Applications

In today's sectors, in which the performance of products is directly linked to reliability and customer satisfaction, environmental testing is crucial. Humidity is one of the more frequently occurring environmental conditions to consider for the longevity of products. High temperature with excessive moisture can cause damage to materials, corrosion to metals, and failure of electrical, electronic, and aerospace components. To determine whether or not a product is resistant to these conditions, manufacturers perform tests using an instrument called a Damp Heat Tester.

The Damp Heat Test Chember is necessary to determine how materials or products will perform when exposed to heat and high humidity over time. It is used in a wide range of industries, including electronics, automotive, aerospace, telecommunications, and packaging, to simulate the natural effects of tropical and humid environments.

What is Damp Heat Tester?

A damp heat tester is an environmental test tool that uses extreme conditions of high relative humidity and high temperature to assess a product’s long-term durability and reliability. In environmental testing, a damp heat tester is important in evaluating the performance of components, electronics or any style of product, as these harsh environmental conditions are expected to be seen during transportation, storage, and use in tropical or humid environments. The test is conducted using cyclic or constant temperature and humidity changes.

How Does Damp Heat Tester Work?

A damp heat tester offers a testing environment where you place a product in an environmental chamber to subject it to a specific time of high temperature and high relative humidity, and also to assess durability and reliability performance.

How it works:

• Heating: The equipment warms the material up to a certain temperature. The heat/thermal energy is transferred to the product via the means of convection and radiation. 
• Humidity Control: A humidifier is utilized to create an elevated level of humidity, usually as part of a refrigeration system with a compressor, that can additionally cool the chamber, which allows control of the desired relative humidity levels.
• Test Conditions: Normal test conditions, like described in IEC 61215, expose a product to relative humidity for a prolonged period of time (i.e., 1000 hours) and see if or where degradation or failure occurs. 
• Results: This chamber (machine/process) permits a manufacturer to imply how a product will behave over time by simulating prolonged exposure to moisture conditions (and temperature fluctuations). This allows product manufacturers to ascertain if there shall be any potential issues with a product relative to material or product degradation and/or corrosion prior to launching to market.
• Outcome: The chamber provides manufacturers with the ability to forecast how their product will behave in the long term by replicating long-term exposure to moisture and temperatures. Manufacturers are proactive in seeing if there are potential issues for the product that may come about due to material degradation or corrosion prior to launching the product.

Damp-Heat Test Procedure

The Damp Heat Test works on the principle of accelerated aging by environmental simulation, in which combined heat and humidity are utilized together to mimic the normal conditions that lead to corrosion, material deterioration, and electrical failure over time.

Otherwise put, the test simulates the hot and humid environment of tropical environments artificially, so manufacturers can forecast long-term product performance within a much shorter period.

Standards Used for Damp Heat Tester

Some common damp heat testing standards are IEC 60068-2-30, IEC 60068-2-78, and IEC 60068-2-38, as well as some national standards like GB/T 2423.3, GB/T 2423.4, and the Indian Standard IS 9000-5-1. These standards state the test methods for constant, cyclic, and composite damp heat conditions to determine a product's capability to withstand high humidity and thermal cycling.

Some of the most commonly used standards are:

• IEC 60068-2-78 for the steady-state damp heat test
• IEC 60068-2-30 for cyclic damp heat test
• ISO 16750-4 for environmental tests for road vehicles
• MIL-STD-810H (Method 507.6) for humidity testing for defense and military equipment
• ASTM D1735 / ASTM D2247 for the resistance of coatings to humidity
• JIS C 60068-2-30 is the equivalent Japanese standard for cyclic damp heat testing

These standards state the test duration, temperature-humidity conditions, and test evaluation criteria to obtain consistent and comparable test results industry-wide.

What is the Damp Heat Test IEC 60068?

In the IEC 60068 family of tests, the damp heat test evaluates the response that electronic products and components will display while in use, stored, or shipped, in a high temperature and humidity environment. The most widely used damp heat test in the family is the cyclic damp heat test, defined by IEC 60068-2-30, with the damp heat cycle approximating natural conditions for durability. 

The cyclic damp heat test is 24 hours of high temperature and humidity followed by a cool humid phase, which is cycled by repeating that procedure, and used to check for possible deterioration from moisture and temperature traveling to cooler surfaces, causing possible condensation on the tested specimen.

What does the test offer?

• Defines durability: It helps to ensure products work properly in high-humidity settings, such as in tropical environments.
• Simulates real-life conditions: The cyclic nature of the test, as stated in IEC 60068-2-30, simulates the regular daily changes in temperature and humidity to which products experience outside or inside of a vehicle.
• Identifies points of failure: It is intended to accelerate corrosion and points of failure that could be caused by moisture, namely, corrosion or electrical issues.

Applications of Damp Heat Tester

Damp heat testers are utilized to measure the endurance of products under a mixture of high heat and humidity by mimicking extreme climatic conditions. Their uses cross multiple industries such as electronics, automotive, solar, and aerospace to guarantee product dependability, avoid material decay, and conduct performance in tropical or humid conditions

The major applications are given below

1. Electronics

The purpose of the damp heat tester is to assess the reliability of electrical devices - printed circuit boards, sensors and semiconductors - in an environment with both high temperature and humidity. A damp heat tester can expose damp heat to find defects of rust, insulation failure, short circuits, etc. A damp heat tester can also help evaluate if a device will operate properly and remain reliable in wet conditions or warm climates.

2. Automotive

Damp heat testing, as it applies to the automotive industry, evaluates the ability of all electrical systems, electronic control units (ECUs), wiring, and materials of the vehicle's passive components to perform in humid and thermal stress. Damp heat testing helps prevent potential faults, including insulation failure, corrosion, or component exhaustion, enhancing the safety, reliability, and performance capacity of the vehicle's exposure to moisture. 

3. Solar

Solar or photovoltaic (PV) modules are evaluated in damp heat tests to verify they can endure long-term high temperature and humidity conditions. Damp heat testing ensures that the solar systems maintain their efficiency, electrical integrity, and structural integrity, particularly in a tropical environment or at the coast with a constant level of moisture.

4. Aerospace and Telecommunications

Damp heat testing confirms that aerospace and telecommunications equipment such as avionics, satellite systems, and outdoor base stations, can resist very high humidity and temperature cycles. It guarantees continuous performance, corrosion immunity, and long-term operation stability of sensitive electronic components under different atmospheric conditions.

5. Materials and Construction

Damp heat testing applies to paints, coatings, laminates, adhesives, and building products to evaluate their resistance to damage that may result from exposure to moisture. The testing of materials will provide an indication of durability over time, adhesion strength, and stability of appearance in service, minimizing the effect of moisture-related problems such as blistering, delaminating, and structural collapse in high humidity and tropical building conditions.

6. Medical Devices

Damp heat testing is the process used to establish the stability, safety, and integrity of medical devices or instruments, such as wearables. The manufacturer has ensured that the materials used are working and sterile and provide safe conditions for shipping, storage, and use under controlled humidity and temperature.

Conclusion 

The Damp Heat Tester is an effective method for testing a product's capacity, suitability for use, and longevity in high-temperature and high-humidity settings. Manufacturers are able to detect defects early enough if they test in an identical environment, so that they can avoid product failure and evaluate suitable reliability.