CERTIFICATION / TEST

The salt spray test is an environmental test designed to assess the corrosion resistance of products or metal materials. It involves creating an artificial salt spray environment using specialized equipment. There are two primary categories of salt spray testing:

Natural Exposure Tests - Rarely performed due to the long duration and labor involved.
Artificial Accelerated Salt Spray Tests - A faster and more controlled method. Here, a saltwater solution is atomized and sprayed in a closed, temperature-controlled chamber. By observing the changes in the sample over time, the corrosion resistance is assessed.


Principles of the Salt Spray Test
Corrosion in most metals occurs in atmospheric conditions containing oxygen, humidity, and other corrosive factors. Salt spray corrosion, one of the most common and destructive forms, involves electrochemical reactions. Chloride ions, highly penetrating and capable of displacing protective oxide layers, play a significant role in this process, leading to material degradation.

Types of Salt Spray Tests


Neutral Salt Spray Test (NSS)


Uses a 5% sodium chloride solution at a neutral pH (6.5–7.2).
Operates at 35°C with a salt deposition rate of 1–2 ml/80 cm² per hour.
Suitable for metals, alloys, conversion coatings, and anodized films.


Acetic Acid Salt Spray Test (AASS)

Involves adding acetic acid to adjust the solution to an acidic pH (3.1–3.3).
Accelerates corrosion three times faster than NSS.
Often used for decorative coatings like copper-nickel-chromium or anodized aluminum.


Copper-Accelerated Acetic Acid Salt Spray Test (CASS)

Includes copper chloride (CuCl₂) to enhance corrosion.
Corrosion rate is eight times faster than NSS.
Suitable for evaluating high-performance decorative coatings.


Cyclic Salt Spray Test

Combines salt spray with alternating humidity cycles.
Commonly used for complex products where internal and external corrosion needs assessment.




Evaluation Methods


Grading Method: Evaluates the ratio of corroded to total surface area.
Weight Loss Method: Measures the weight difference before and after testing to determine material degradation.
Visual Inspection: Assesses the presence of corrosion visually, often used in product standards.
Statistical Analysis: Provides confidence levels for data and trends in corrosion resistance.


Common Standards for Salt Spray Tests


GB/T 10125-2021: Artificial Atmosphere Corrosion Test.
GB/T 2423.17-2008: Environmental Testing for Electrical Products.
IEC 60068-2-11: Salt Spray Testing for Electronic Products.
GJB 150.11A-2009: Salt Spray Testing for Military Equipment.


Factors Affecting Test Results


Salt solution concentration
Temperature and humidity
Sample placement angle
Spraying method
Test duration and interruptions

What is Ingress protection (IP)?

IP code or ingress protection code is defined by the International Electrotechnical Commission (IEC) under the international standard IEC 60529 which classifies and provides a guideline to the degree of protection provided by mechanical casings and electrical enclosures against intrusion, dust, accidental contact, and water. It is published in the European Union by the European Committee for Electrotechnical Standardization (CENELEC) as EN 60529.

The standard aims to provide users more detailed information than vague marketing terms such as waterproof. For example, a cellular phone rated at IP67 is "dust resistant" and can be "immersed in 1 meters of freshwater for up to 30 minutes". Similarly, an electrical socket rated IP22 is protected against insertion of fingers and will not become unsafe during a specified test in which it is exposed to vertically or nearly vertically dripping water. IP22 or IP2X are typical minimum requirements for the design of electrical accessories for indoor use.

The digits indicate conformity with the conditions summarized in the tables below. The digit 0 is used where no protection is provided. The digit is replaced with the letter X when insufficient data has been gathered to assign a protection level. The device can become less capable, however it cannot become unsafe.

Protection against solid objects
0 – No protection/ No test required
1 – Protected against objects greater than 50mm diameter
2 – Protected against objects greater than 12.5mm diameter, such as a finger
3 – Protected against objects greater than 2.5mm
4 – Protected against objects greater than 1.0mm such as wire
5 – Ingress of dust is not totally prevented but dust does not enter in harmful quantities to interfere with the correct operation or impair safety
6 – No ingress of dust permitted

Protection against water
0 – No protection / No test required
1 – Protected against falling drops of water
2 – Protected against drops falling at 15° in 4 fixed positions
3 – Low pressure spray – similar to shower head at up to 60° from vertical tested using an oscillating tube with an arc of 60° for ten minutes
4 – Low pressure spray – similar to shower head – as per numeral 3 but 180° for 10 minutes
5 – Medium pressure jet – 6.3mm diameter, similar to garden hose – from any angle for 3 minutes at a distance of 2.5-3 metres.
6 – High pressure jet – 12.5mm diameter, similar to fire hose – from any angle for 3 minutes at a distance of 2.5-3 meters.
7 – Immersion – for temporary immersion in water under set conditions – 1 metre for 30 minutes
8 – Protected against the effects of continuous immersion in water, ingress of water in quantities causing harmful effects shall not be possible. Conditions should be more severe than for numeral 7.
9 – Steam clean, high pressure, high temp jet wash to DIN40050 (German Std), extends BS EN 60529:1992

IP Enclosures at Deltron

At Deltron Enclosures, we can offer IP54 enclosures, which are suited to light duty environments that may require some level of protection from dust.

For more demanding applications, we also manufacture IP66 and IP68 enclosures. These are suited to industries mentioned previously in this article, where the applications are located in tough environments and therefore ingress protection is a priority.

In addition, our IP66 and IP68 enclosures are available in a heavy duty version for a durable enclosure. They are often used for deep water applications, or when the engineer requires resilient casing for the electronic components.

WHAT ARE E-MARK?
In order for lighting products to be traded on the European market, they must meet certain requirements in the areas of safety, health and the environment. For example, with regard to the safety of drivers of vehicles and their surroundings when it comes to lighting, regulations have been drawn up by the Economic Commission for Europe: ECE. Directives (indicated with the letter R) lay down, for example, the amount of light, visibility, flashing frequency, etc. of headlights, rear lights, flash units, work lights, etc.

WHAT ARE E-MARK?
In order for lighting products to be traded on the European market, they must meet certain requirements in the areas of safety, health and the environment. For example, with regard to the safety of drivers of vehicles and their surroundings when it comes to lighting, regulations have been drawn up by the Economic Commission for Europe: ECE. Directives (indicated with the letter R) lay down, for example, the amount of light, visibility, flashing frequency, etc. of headlights, rear lights, flash units, work lights, etc.

WHAT ARE E-MARK?
In order for lighting products to be traded on the European market, they must meet certain requirements in the areas of safety, health and the environment. For example, with regard to the safety of drivers of vehicles and their surroundings when it comes to lighting, regulations have been drawn up by the Economic Commission for Europe: ECE. Directives (indicated with the letter R) lay down, for example, the amount of light, visibility, flashing frequency, etc. of headlights, rear lights, flash units, work lights, etc.

WHAT ARE E-MARK?
In order for lighting products to be traded on the European market, they must meet certain requirements in the areas of safety, health and the environment. For example, with regard to the safety of drivers of vehicles and their surroundings when it comes to lighting, regulations have been drawn up by the Economic Commission for Europe: ECE. Directives (indicated with the letter R) lay down, for example, the amount of light, visibility, flashing frequency, etc. of headlights, rear lights, flash units, work lights, etc.

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