Salt Spray Test Cabinet Controlled Salt Spray, Paint Corrosion Testing and LIB Series

Accurate, controlled salt-spray conditions are the cornerstone of coating corrosion assessment - only with stable salt concentration, deposition rate, and temperature/humidity control can test results be comparable and effectively simulate real-world failure mechanisms.

LIB's Salt Spray Test Cabinets deliver repeatable salt-spray conditions (precise mix, uniform atomization, preheated air, PID control) and come in Basic, Cyclic, and SO₂ bench or walk-in versions.

【Delivering Controlled Salt - Spray Conditions of Salt Spray Test Cabinet】

To consistently and reliably generate a salt spray environment, the key factors are concentration/pH, spray and deposition uniformity, temperature control, and real-time monitoring and protection. The main procedures and key points of LIB's Salt Spray Test Cabinet are as follows:

Salt solution preparation and mixing

A 5% NaCl standard solution is used, with pH controlled between 6.5 and 7.2. A precision mixing and heating system within the saltwater tank ensures solution uniformity and prevents clumping.

Spray and deposition rate control

• Use a quartz nozzle + salt spray tower (spray tower) and maintain the spray pressure at 83 kPa according to standards to ensure stable spray fineness and prevent crystallization blockages.
• Deposition rate is measured in real-time/periodically using a spray collector and graduated cylinder, with a target deposition rate of 1–2 mL/80 cm²·h. Deposition variations across different locations are controlled to approximately 0.2 mL/80 cm²·h (the LIB Salt Spray Test Cabinet can achieve this level).

Temperature and Humidity Preheating and Control

• The LIB Salt Spray Test Cabinet sets and controls pre-spray air preheating via a saturated barrel. The chamber maintains an exposure temperature of 35 ± 2°C, meeting ASTM B117 standards, with temperature control accuracy maintained at ±0.5°C.
• PT-100 Class A temperature sensors + PID controllers ensure stability and minimize fluctuations that could interfere with deposition and paint corrosion rates.

Sealing, Fog Removal, and Observation

• The Salt Spray Test Cabinet features an integrated fiberglass-reinforced plastic (FRP) structure for enhanced sealing and corrosion resistance. An automatic salt fog removal (demist) system facilitates observation of sample surfaces after testing.
• An automatic demisting and exhaust system minimizes changes in deposition caused by fluctuations inside the chamber.

Automation and safety monitoring controller

• PID control combined with a multilingual touchscreen allows for the presetting of up to 120 programs, real-time recording (temperature, spray time, pH, deposition rate), and support for USB/Ethernet export.
• Safety protections (dry burn, over-temperature, leakage, water shortage, etc.) ensure stable long-term operation and personnel safety.

Additionally, regular maintenance (nozzle cleaning, stirring system inspection, sensor calibration) and pre-test idle runs/calibration are standard practices to ensure the reproducibility of the "controlled salt spray environment."

【Key of Salt Spray Test Cabinet for Assessing Paint Corrosion Resistance】

Assessing the corrosion resistance of coatings involves more than simply placing samples in a chamber and spraying them with salt spray. It is essential to ensure that the test can simulate the relevant causes of coating failure and provide repeatable, quantifiable results.

Common causes of failure in coating corrosion testing include: ① corrosion of the metal substrate (salt water or moisture enters after the coating is damaged) ② blistering and cracking of the coating ③ decreased adhesion between the coating and the substrate, leading to peeling ④ structural changes in the material due to prolonged exposure to a humid, salt spray environment

Key points of the Salt Spray Test Cabinet include:

Deposition rate and concentration stability → accelerated but comparable

Requirements: a deposition rate of 1–2 mL/80 cm²·h that is stable and measurable; salt solution concentration of 5% ±1%, pH 6.5–7.2. Only under these conditions can the data be compared across batches/devices.

Spray coverage uniformity and sample placement

Spray tower design must eliminate blind spots. Using V-shaped channels, round rods, or custom fixtures to ensure consistent sample surface orientation and spacing. Deposition differences at different locations should be within acceptable limits (≤0.2 mL difference).

Temperature, humidity, and circulation method

• Single-state salt spray (NSS) is suitable for basic salt resistance testing; however, coatings in real-world environments often experience damage caused by wet-dry cycles, temperature fluctuations, and polluting gases (e.g., SO₂). Therefore:
• For decorative/high-end coatings, the Salt Spray Test Cabinet should be used for CASS/AASS (copper-accelerated or acidic).
• For outdoor/automotive applications, a cyclic (wet-dry cycle) method should be used to detect issues such as cracking, blistering, and scribe creep earlier.

Testing criteria

During testing, we focus on coating failure phenomena. To ensure reliable results, clear testing methods (such as direct observation, microscopic examination, scratch testing, etc.) must be defined in advance, and evaluations should be conducted according to standardized criteria (e.g., ASTM or ISO grading systems).

Repeatable recording and traceability

The LIB Salt Spray Test Cabinet automatically records (temperature, spray time, pH, deposition) and stores data. Test procedures (exposure time, cycle steps) are pre-set and versioned for easy control.

Sample Preparation and Control Groups

Sample surface treatment, coating thickness, and curing conditions must be strictly consistent. Control samples (reference panels) are kept on hand to assess equipment and batch variations.

Standard and Method Selection

Select standards based on testing objectives: ASTM B117, ISO 9227, ASTM G85, etc.

The "key" to evaluating coatings is to use appropriate test modes (NSS/CASS/AASS/cyclic/SO₂) to replicate the primary test points of the material in the target environment, and to support the comparability and interpretability of results with stable, quantifiable deposition and temperature control data.

【LIB Salt Spray Series: Basic, Cyclic, SO₂ –Small-Sized, Walk-In Chambers】

Series Function Differences

1. Salt Spray Test Cabinet (Basic Type)

• Test Mode: Salt Spray + Temperature
• Standards: ASTM B117 / ISO 9227 
• Accuracy: Temperature ±2°C / Humidity ±5% RH (Suitable for routine quality inspection and material batch screening)
• Applications: Metal parts, electrical enclosures, plastic parts, and basic coating inspection.

2. Cyclic Salt Spray Chamber (Cyclic Type etc.)

• Test Mode: Salt Spray → High Humidity → Temperature Cycling → Dry Airflow (automatic switching between four modes)
• Standards: Cyclic Appendix of ASTM B117, ASTM G85, relevant annexes of ISO standards
• Accuracy: Temperature ±0.5°C / Humidity ±2% RH (stricter control)
• Applications: Coating R&D, automotive parts, military/high-reliability products, and realistic simulation of fatigue failures caused by wet-dry cycles.

3. SO₂ Corrosion Test Chamber (with SO₂ contaminated gas)

• Test Mode: Salt spray + SO₂ contaminated gas + humidity + temperature
• Standards: ISO 6988 / ASTM G87 (Sulfur Corrosion Resistance Test)
• Accuracy: Temperature ±1°C / Humidity ±3% RH
• Applications: Industrial atmospheres, sulfur-containing environments (power plants, paper mills, ports, vehicle emissions-sensitive components), and evaluation of coatings/materials with sulfur corrosion resistance requirements. The LIB test chamber's SO₂ treatment system includes safety measures for toxic gas emission, absorption, and neutralization (NaOH tank), along with specialized ventilation and emission compliance design.

Small Salt Spray Chamber vs. Walk-In Salt Spray Chamber

1. Small Salt Spray units (e.g., S-150/S-250/S-750)

• Advantages: Compact footprint, low energy consumption, suitable for routine testing of parts and samples in laboratories or quality control rooms (internal dimensions: 110–410 L), enabling parallel testing of multiple small samples.
• Features: Built-in 30 L saltwater tank, easy management of deposition uniformity, cost-effective.
• Applications: Coating laboratories, early-stage R&D screening, etc.

2. Walk-In Salt Spray Chamber

• Advantages: Can test large components (vehicle components, pipes, panels, etc.) or conduct simultaneous testing of batch samples. Facilitates comprehensive performance evaluation of actual assembled components.
• Application scenarios: Industrial validation, large-scale component corrosion resistance testing, customer-specific/certification testing.

Selection recommendations (how to choose Basic/Cyclic/SO₂ and size)

• Purpose > Environmental reproducibility:

① For batch quality inspection only: Choose Basic Salt Spray Chamber.

② Need to simulate real-world climate conditions (rain/fog-dry-hot/cold cycles): Select Cyclic Salt Spray Chamber.

③ Target environment contains sulfur or severe industrial pollution: Select SO₂ Cyclic Salt Spray Chamber (and configure treatment systems).

• Sample Size and Quantity:

Small parts, panels, test specimens → Small standing Salt Spray Chambers(S-150/250/750).

Large components or large quantities of components → Walk-in Salt Spray Chamber.

LIB provides a 3-year warranty with lifetime support. If any problem cannot be fixed during the warranty period, we'll replace it at no cost. Our 24/7 English-speaking after-sales team is always ready to help, and we offer fast delivery within 7–15 days.

Reach out to LIB to find the right corrosion testing solution and see how our customizable salt spray test cabinets can help you improve product performance and reliability.