ConstaSal® TR – Salt Spray Test Chamber
400, 1000, and 2500-litre test volumes • Application-specific 1200- and 3000-litre custom options • S salt spray system • Manual M-TR control
ConstaSal® TR is a top-loading, chest-type corrosion test chamber developed for subjecting large and bulky samples to standardised salt spray tests.
Part of the Liebisch M-TR chamber family, the system enables neutral salt spray (NSS), acetic acid salt spray (AASS), and copper-accelerated acetic acid salt spray (CASS) tests to be performed under controlled and repeatable conditions.
With test volume options of 400, 1000, 1200, 2500, and 3000 litres, the chamber can accommodate not only test panels but also large components or parts whose geometry makes them difficult to place in cabinet-type chambers. For heavy samples, the chamber’s load capacity and suitable support equipment should be assessed separately.
What Is ConstaSal TR Used For?
Salt spray tests are used to evaluate the behaviour of metallic materials and protective coatings in a specified corrosive test atmosphere.
ConstaSal TR can be used to expose the following to controlled salt spray conditions:
- Painted and organically coated metal surfaces,
- Electroplated and metallic coatings,
- Aluminium and aluminium alloys,
- Anodic oxide coatings,
- Conversion coatings,
- Automotive and automotive supplier components,
- Large machinery and equipment components,
- Bulky or heavy test samples.
After testing, changes such as red rust, white corrosion, blistering, coating delamination, surface deterioration, and corrosion progression around a scribe can be examined using the evaluation methods specified in the relevant product standard.
Salt spray testing does not directly determine a product’s actual service life. Its primary purpose is to evaluate materials, coatings, or production batches under the common conditions specified by the relevant standard.
Salt Spray Tests That Can Be Performed
Neutral Salt Spray Test – NSS
NSS is the most widely used continuous salt spray test method. A sodium chloride solution prepared within a neutral pH range is atomised into the chamber using conditioned compressed air to create a uniform fog.
The NSS method is particularly used for the quality control of:
- Metals and metal alloys,
- Anodic or cathodic metallic coatings,
- Conversion coatings,
- Anodic oxide coatings,
- Organic coatings on metals.
Many salt spray applications covered by ASTM B117 and TS EN ISO 9227 are based on this method.
Acetic Acid Salt Spray Test – AASS
In the AASS method, the salt solution is acidified with acetic acid to create a more acidic test atmosphere. This method is particularly used to evaluate decorative copper–nickel–chromium or nickel–chromium coatings, as well as anodic and organic coatings on aluminium.
The test solution, temperature, and pH conditions should be prepared in accordance with the current version of the applicable standard.
Copper-Accelerated Acetic Acid Salt Spray Test – CASS
In the CASS test, copper salt is added to an acetic acid salt solution to create a more aggressive test environment. The method is particularly used for the quality control of decorative nickel–chromium and copper–nickel–chromium coatings.
CASS tests may require a higher operating temperature than standard NSS tests. ConstaSal TR may therefore need to be configured with the high-temperature operating option for temperatures up to 70 °C.
The double-walled, thermally insulated lid used on chest-type chambers helps limit energy loss during high-temperature tests.
Advantages of the Chest-Type Design
The top-loading design of ConstaSal TR makes it easier to place wide or bulky samples inside the chamber.
This chamber design is particularly advantageous for applications involving:
- Wide parts that are difficult to load through a cabinet door,
- Long test panels,
- Heavy metal components,
- Welded structures,
- Automotive and machinery parts,
- Testing a large number of samples simultaneously.
The 400- and 1000-litre models feature a lid system with dual gas struts. The 2500-litre model uses pneumatic assistance to ensure safe and controlled movement of the large lid.
Standard models are supplied with a highly insulated lid. A transparent lid option can also be considered for applications requiring observation of the chamber interior during testing.
ConstaSal TR According to the Liebisch System Code
| Code | Description |
|---|---|
| S | Continuous salt spray system |
| M | Manual control level |
| TR | Chest-type test chamber |
| 400/1000/2500 | Test chamber volume in litres |
ConstaSal M-TR is equipped exclusively with the S salt spray process. If salt spray and condensation humidity tests need to be performed in the same chamber, the programmable ConstaTwin M-TR should be considered. For cyclic tests comprising multiple climatic stages, ConstaMatic A-TR models should be evaluated.
For detailed information about Liebisch system codes and other process combinations, please visit the Liebisch Process Systems page.
Applicable Standards
According to the Liebisch standards matrix, the following test standards can be performed using the S system of ConstaSal TR:
ASTM B117 – Standard Practice for Operating Salt Spray (Fog) Apparatus
Specifies the apparatus, operating conditions, and procedures required to create and maintain a salt spray test environment.
ASTM B368 – Standard Test Method for Copper-Accelerated Acetic Acid-Salt Spray (Fog) Testing (CASS Test)
Specifies the operating conditions for copper-accelerated acetic acid salt spray testing.
TS EN ISO 9227 – Corrosion Tests in Artificial Atmospheres — Salt Spray Tests
Covers neutral salt spray (NSS), acetic acid salt spray (AASS), and copper-accelerated acetic acid salt spray (CASS) methods.
TS EN 13523-8 – Coil Coated Metals — Test Methods — Part 8: Resistance to Salt Spray (Fog)
Used to evaluate the resistance of coil-coated metal surfaces to a salt spray environment.
TS EN 60068-2-11 – Environmental Testing — Part 2-11: Tests — Test Ka: Salt Mist
Defines a method for evaluating the resistance of electrical, electronic, and similar products to salt mist.
TS ISO 9022-4 – Optics and Photonics — Environmental Test Methods — Part 4: Salt Mist
Intended to evaluate the resistance of optical instruments and related components under saline atmospheric conditions.
JIS Z 2371 – Methods of Salt Spray Testing
The Japanese Industrial Standard for conducting salt spray tests.
MIL-STD-202, Method 101 – Salt Atmosphere (Corrosion)
Used to evaluate the corrosion resistance of electrical and electronic components under salt-laden atmospheric conditions.
MIL-STD-810, Method 509 – Salt Fog
A military environmental test method for evaluating the resistance of equipment and materials to the effects of salt fog.
Standards That May Require Optional Equipment
The Liebisch standards matrix indicates that the following tests can be performed using the S system of ConstaSal TR, subject to optional equipment and manufacturer approval:
- GME 60205
- GMI 60206
- GME 60207
The full designation, current revision, and test conditions of the relevant standard should be provided before ordering. This allows the required temperature range, spray system, measuring equipment, and additional accessories to be determined correctly.
Operating Principle
The prepared test solution is transferred to the spray unit through a precision dosing system. Conditioned compressed air and the test solution are atomised into the chamber through a precision twin-fluid nozzle, creating a uniform salt fog.
Before testing, the operator:
- Sets the test chamber temperature.
- Sets the humidifying tower temperature.
- Adjusts the spray air pressure.
- Sets the test solution dosing rate.
- Checks the fog distribution inside the chamber using collection vessels.
The digital dosing pump helps maintain a stable supply of the solution. Throughout the test, temperature, air pressure, solution level, collected solution volume, and distribution within the chamber should be monitored in accordance with the relevant standard.
ConstaSal M-TR is equipped with a humidifying tower featuring a constant-level system. The system automatically draws the required water from a pressurised demineralised water line.
The inlet and outlet pressures of the humidifying tower can be monitored using the pressure gauges on the chamber. Warning and protection systems for low and high pressure help ensure that the spray air is properly conditioned.
To ensure reliable test results, the compressed air supplied to the chamber must be free from oil, water, dust, particles, and other contaminants. A compressed-air conditioning unit with a pressure gauge can be used where necessary.
The ConstaSal TR test area is manufactured from glass-fibre-reinforced plastic materials to withstand the high-humidity test atmosphere. Minimising corrosion-sensitive metal components inside the chamber helps extend its service life and reduces the risk of foreign corrosion products affecting the test atmosphere. This construction also limits maintenance requirements and provides a more stable operating environment during long-duration tests.
Large heating sections integrated into the front and rear walls are isolated from the corrosive test atmosphere. The heating system is designed to provide uniform temperature distribution throughout the test volume and support energy-efficient operation.
When the test is complete or the samples need to be inspected, the chamber lid should not be opened immediately. Compressed air should first be introduced into the chamber to remove the concentrated salt fog through the exhaust line.
This process helps reduce the release of corrosive fog into the laboratory, its effects on nearby instruments and equipment, and the operator’s exposure to the concentrated test atmosphere.
ConstaSal TR has separate outlets for drainage and air exhaust. A removable strainer in the drainage line helps prevent corrosion residues detached from the samples from blocking the drain.
The chamber’s exhaust and drainage connections should be prepared in accordance with the manufacturer’s technical requirements before installation.
The temperatures of the test chamber and humidifying tower are set independently. PID control parameters defined according to the chamber volume help limit fluctuations in the test temperature.
When the optional timer is used, the chamber can:
- Display the test duration,
- Stop the test when the specified time has elapsed,
- Facilitate the monitoring of long-duration tests.
An optional data logging system can be used for applications requiring temperature values to be recorded. If automatic programming, cycle management, and more comprehensive recording features are required, the ConstaMatic A-TR series should be considered.
The appropriate test volume should not be determined solely by whether the sample fits inside the chamber. The salt fog must reach the samples uniformly, and solution runoff from one sample must not drip onto the others.
The following information should be evaluated together when selecting a model:
- Sample width, length, and height,
- Sample weight,
- Number of samples to be tested simultaneously,
- Sample positioning angle required by the standard,
- Required spacing between samples,
- Sample holders to be used,
- Type of test solution,
- Required test temperature,
- Daily or annual testing capacity.
For heavy components, a reinforced base structure and mesh sample support system may be selected. For very large parts or samples with special geometries, non-standard chamber volumes and custom sample supports can be designed on a project-specific basis.
Optional Accessories and Systems
ConstaSal TR can be configured with the following options according to the application requirements:
The suitability of each option should be assessed together with the chamber volume and the applicable test standard.
Which Chamber Should You Choose?
If you intend to perform continuous salt spray tests on large or heavy samples, the chest-type ConstaSal M-TR may be a suitable solution.
Share your intended test standard, test cycle, sample dimensions, and required capacity with us so we can assess the necessary process systems and a suitable chamber configuration together.
Contact us for assistance with selecting the appropriate Liebisch process system and chamber, and for a technical quotation.
| Product Code | Model | Test Volume |
|---|---|---|
| 2304 5012 | ConstaSal® S 400 M-TR Manually controlled, chest-type salt spray test chamber. | 400 liters |
| 2310 5012 | ConstaSal® S 1000 M-TR Manually controlled, chest-type salt spray test chamber. | 1000 liters |
| 2310 5012-G | ConstaSal® S 1000 M-TR‑G** Salt spray test chamber with a three-part modular chamber construction. | 1000 liters |
| 2310 5012-K | ConstaSal® S 1000 M-TR-K** Short-body salt spray test chamber without a tank enclosure. | 1000 liters |
| 2312 5012 | ConstaSal® S 1200 M-TR Manually controlled, chest-type salt spray test chamber. | 1200 liters |
| 2325 5014 | ConstaSal® S 2500 M-TR Manually controlled, chest-type salt spray test chamber suitable for large samples. | 2500 liters |
| 2330 5014 | ConstaSal® S 3000 M-TR Manually controlled, chest-type salt spray test chamber suitable for large samples. | 3000 liters |
** In M-TR-G, the -G suffix denotes the three-part modular construction; in M-TR-K, the -K suffix denotes the short-body design without a tank enclosure. These two suffixes do not indicate a gas dosing or condensation humidity system.
