Corrosion Testing Instruments

In salt spray testing, a test solution prepared at a specified concentration is atomised into a fine mist inside the test chamber using compressed air. The specimens are exposed to a corrosive atmosphere in which the temperature and solution properties are carefully controlled.

These chambers can be used to perform various salt spray test methods, including:

• NSS – Neutral Salt Spray Test
• AASS – Acetic Acid Salt Spray Test
• CASS – Copper-Accelerated Acetic Acid Salt Spray Test

Commonly associated with standards such as ISO 9227 and ASTM B117, these tests are used to comparatively evaluate the corrosion resistance of coatings, metal surfaces, fasteners and surface treatment processes.

Relevant chambers:

In condensation humidity testing, demineralised water at the bottom of the chamber is heated to create a high-relative-humidity test environment. Condensation forming on the specimen surfaces enables the resistance of coatings and materials to continuous or cyclic humidity conditions to be evaluated.

Depending on the chamber configuration, constant condensation humidity conditions can be applied, or humidification stages can be combined with ventilation and cooling stages under ambient conditions. These tests are used particularly to evaluate blistering, corrosion, loss of adhesion and other moisture-related deterioration in paints and coatings.

Condensation humidity tests can be performed in accordance with various national and industry-specific methods, particularly the ISO 6270 series.

Relevant chambers:

Combined corrosion test chambers enable salt spray and condensation humidity tests to be performed within the same chamber. In manually operated models, the user changes the test stages, while different processes can be carried out in the same test space depending on the chamber configuration.

This design can provide space and investment advantages for laboratories that wish to perform salt spray and condensation humidity tests in a single chamber rather than using separate instruments.

Relevant chambers:

In cyclic corrosion testing, specimens are not exposed to a single, constant corrosive atmosphere. Different stages—such as salt spray, condensation humidity, controlled relative humidity, ventilation, hot air, drying, cooling or water spray—can be applied consecutively for defined periods.

These methods aim to simulate the variable environmental conditions that materials may encounter during actual service more comprehensively than conventional continuous salt spray tests. Programmable chambers are particularly suitable for automotive applications and multi-stage testing programmes.

The Liebisch ConstaMatic series can be configured by combining the necessary process systems in accordance with the relevant test standard or company-specific test cycles.

Relevant chambers:

For applications beyond standard salt spray, condensation humidity and cyclic testing, custom-built chambers or application-specific modifications to standard models can be developed.

These may include custom specimen holders, alternative lid and door systems, specialised cable ports, adapted drainage systems, non-standard test volumes and user-specific process combinations.

Specialised systems such as the Dippomat can be used for tests requiring alternating immersion and condensation humidity stages.

Relevant chambers:

Desk-type chambers are compact systems with a test volume of 300 litres. The Constanzo K and KB models can be configured with different equipment options for condensation humidity tests, with or without pollutant gases.

The K 300 series is designed for constant condensation humidity conditions, while the KB 300 series can perform constant and variable humidity cycles through its automated ventilation system. Depending on the model, options may include elevated operating temperatures, automatic water filling and draining, and data transfer. Liebisch’s current desk-type range also includes the ConstaMatic S 300 A-TI model for salt spray testing.

Desk-type systems provide a compact solution for laboratories with limited space and for testing smaller specimens.

Cabinet-type chambers provide easy access to specimens through their front-loading design. Liebisch’s current cabinet-type product range includes test volumes of 400, 1,000, 2,000 and up to 3,000 litres.

This design can accommodate a wide range of configurations, from manually operated salt spray or condensation humidity chambers to automated cyclic systems combining salt spray, humidity, ventilation, hot air, controlled relative humidity, water spray and cooling stages. Available test volumes vary depending on the selected product series and process combination.

Cabinet-type chambers are particularly suitable for applications where front loading, specimen visibility and vertical positioning are important.

In chest-type chambers, the test area is accessed through a top-opening lid. This design can facilitate the placement of multiple specimens or long and bulky components inside the test chamber.

Liebisch’s current chest-type range includes test volumes of 400, 1,000, 1,200, 2,500 and up to 3,000 litres. However, not every volume may be available for all product series and process combinations. Manual and automated configurations are available for salt spray, condensation humidity, combined and programmable cyclic corrosion testing.