To choose a suitable salt spray test chamber sample rack, you need to consider the material, structure, function and test requirements from multiple dimensions. The core points are as follows:
1. Select materials according to sample materials and test purposes
- Conventional metal/coated samples: Choose PVC or PP materials, which are resistant to salt spray corrosion and low cost (such as automotive accessories, hardware).
- High-end or special environment materials (such as aerospace, semiconductors): Choose fluoroplastics (PTFE), which have strong corrosion resistance and avoid material contamination.
- Involving galvanic corrosion tests (different metal contacts): Choose an insulating sample rack (with epoxy coating on the surface) to prevent electrochemical reactions between the bracket and the sample.
2. Choose a structure according to sample shape and installation requirements
- Small parts/thin sheets (such as screws, gaskets, test pieces): Choose a multi-layer tray type, which is layered and flat to save space, and the bottom guide hole prevents liquid accumulation.
- Plates/chains/samples that need to be exposed on both sides: Choose a rack type, which is hung vertically to avoid surface liquid accumulation and ensure that both sides are evenly fogged.
- Samples with irregular shapes (such as castings, valves, curved parts): select the rotating type, which rotates 360° to make all surfaces contact with salt spray and simulate dynamic environments.
Select functions based on test standards and scenarios
- Simulate actual installation angles (such as car chassis, exterior wall paint): select the inclined sample holder, fixed at a standard angle (15°/30°), and fit the rain scouring scene.
- The uniformity of salt spray needs to be strictly controlled: ensure that the sample holder structure does not block the spray (such as the rack spacing ≥5cm) to avoid local concentration differences.
Other key considerations
1. Anti-liquid accumulation design: avoid grooves and right-angle corners on the surface of the sample holder to prevent salt spray droplets from remaining and affecting the test accuracy.
2. Load-bearing capacity: select the bracket strength according to the sample weight (such as large plates require reinforced PP brackets to avoid deformation).
3. Standard adaptability: Refer to the test standard requirements (such as GB/T 10125 stipulates that the sample is at a 30° angle to the vertical direction), and select a fixed frame with the corresponding angle.
4. Maintenance cost: PVC/PP materials are easy to clean and have a long life (5-8 years), while fluoroplastics are expensive but suitable for high-frequency and rigorous testing.
Simple selection process
1. Clarify the sample material (metal/plastic/coating) and test standards (such as ASTM B117, ISO 9227).
2. Determine the sample shape (plane/three-dimensional/irregular) and installation method (hanging/flat/tilted).
3. Evaluate environmental requirements (whether it is necessary to simulate dynamic, galvanic corrosion and other scenarios).
4. Compare the corrosion resistance, structural compatibility and cost of the material, and give priority to the solution that balances adaptability and economy.
For example: to test the salt spray resistance of automobile steel plate coating, you can choose a PVC hanging sample holder, which is fixed at a 30° tilt. It not only meets the GB/T 10125 standard, but also avoids liquid accumulation on the coating surface, ensuring reliable test results.
