Operation of Composite Salt Spray Test Chamber: Pitfall Avoidance Guide and Core Precautions

    The composite salt spray test chamber is core equipment for corrosion reliability testing of products such as metals and coatings, and its test data directly affects quality evaluation. However, negligence of details during actual operation often leads to distorted results. This article sorts out common mistakes and precautions to improve the standardization of tests.

I. Common Mistakes During Operation

(1) Pre-test Preparation: Basic Omissions Lay Hidden Risks

1. Non-standard salt solution preparation: Estimating salt dosage by experience or failing to use a balance with an accuracy of ≥0.1g easily causes concentration deviation from standards (e.g., 5% sodium chloride solution); using tap water instead of deionized water introduces interfering ions; injecting insufficiently mixed solution tends to clog nozzles and result in uneven salt spray distribution.

2. Improper sample treatment and placement: Unremoved oil and rust on the sample surface prevent salt spray from contacting the substrate; overlapping samples, insufficient spacing, or failure to align with the spray direction at an angle of 15°–30° all lead to data deviation.

3. Perfunctory equipment inspection: Insufficient water in the liquid storage tank may interrupt the test; salt deposits blocking nozzles and air pipes cause inadequate salt spray; uncalibrated temperature and humidity sensors result in loss of control over test conditions.

(2) During the Test: Improper Operation Causes Data Invalidity

1. Arbitrary adjustment of test parameters: Unauthorized modification of parameters such as temperature and salt spray volume leads to inaccurate data; frequent door opening midway disrupts the stable temperature and humidity environment inside the chamber.

2. Neglect of abnormal condition handling: Failure to shut down and troubleshoot anomalies (e.g., uneven salt spray, temperature/humidity fluctuations) results in distorted data. For instance, unaddressed abnormal salt spray deposition (1–2mL/(80cm²·h)) will make corrosion evaluation deviate from actual conditions.

3. Incomplete data recording: Only recording the start and end time without real-time logging of parameters (e.g., temperature and humidity); failing to timely document sample corrosion phenomena impairs subsequent analysis.

 (3) Post-test: Improper Follow-up Affects Equipment Service Life and Data Analysis

1. Inadequate equipment cleaning: Residual salt solution corrodes the chamber and pipelines; salt deposits block nozzles and atomizers; corrosion products on the chamber wall contaminate subsequent samples.

2. Rash sample treatment and analysis: Failure to rinse and dry samples in accordance with standards allows residual salt to continue corroding the samples; relying solely on visual observation without instrumental quantitative data leads to unscientific conclusions.

3. Lack of equipment maintenance: Not inspecting sealing rings, lubricating components, or cleaning filters results in frequent equipment failures and shortened service life.

II. Core Precautions: Ensure Test Accuracy and Equipment Stability

1. Standardize solution preparation: Prepare solutions in accordance with standards such as GB/T 10125, weigh salt with a precision balance and use deionized water, verify concentration with a densitometer, and inject the solution after thorough mixing and standing.

2. Standardize sample operation: Degrease, derust, and dry samples; ensure sample spacing ≥20mm, distance from chamber wall ≥50mm, and place samples at 15°–30° to prevent shielding.

3. Comprehensively inspect equipment before testing: Check water level, remove salt deposits, calibrate sensors, and verify airtightness to ensure test conditions meet requirements.

4. Stabilize and control test parameters: Prohibit modification of core parameters; limit door opening time to ≤1 minute; record data hourly; shut down and troubleshoot anomalies before retesting.

5. Maintain and clean equipment post-test: Drain and rinse the equipment thoroughly; process samples in a standardized manner and conduct instrumental analysis; regularly replace filters, inspect sealing rings, and keep detailed maintenance records.

III. Conclusion

    The quality of composite salt spray test chamber operation hinges on standardized procedures. Avoiding common mistakes and strictly following precautions ensures data accuracy to support product quality control, while extending equipment service life and reducing costs. Standardization is the core of accurate testing.