Controlled ASTM B117 and ISO 9227 Salt Spray Exposure
DERUI salt spray corrosion test chambers create a repeatable salt-fog environment for comparing the corrosion resistance of metals, coatings, plating and surface treatments. Configure the chamber for the required NSS, AASS or CASS procedure and verify the corrosive environment before testing products.
What Salt Spray Results Can Tell You
Salt spray testing is useful for quality control, coating comparisons and detecting pores, discontinuities or processing changes. The product specification—not ASTM B117 or ISO 9227 alone—defines specimen type, exposure duration and acceptance criteria.
Coatings and Plating
Compare zinc, nickel/chromium, conversion coatings, anodized surfaces, paint systems and temporary protection.
Production Quality
Detect changes in pretreatment, coating thickness, curing, sealing or handling using a consistent reference test.
Component Validation
Expose fasteners, stampings, brackets, enclosures and finished parts according to the customer product specification.
NSS, AASS and CASS Are Different Procedures
| Procedure | Primary use | Configuration implications |
|---|---|---|
| NSS | Neutral salt spray for metals and protected/coated metallic materials | Neutral sodium-chloride solution, controlled fog and chamber temperature per the selected standard |
| AASS | Acetic acid salt spray, especially for selected decorative coatings | Acidified solution; compatible plumbing, cleaning and pH verification required |
| CASS | Copper-accelerated acetic acid salt spray for copper/nickel/chromium or nickel/chromium decorative coatings | Higher test temperature and copper-containing acidic solution; dedicated contamination controls recommended |
ISO 9227:2022 covers all three. ASTM B117 describes continuous salt-fog apparatus and operation; it does not automatically establish AASS/CASS or a product pass/fail requirement.
What Must Be Confirmed on the DERUI Quotation
Workspace and Specimen Layout
Internal dimensions, usable volume, rack geometry, specimen angle, loading mass and clearance from walls, collectors and atomizers.
Fog Generation
Atomizer quantity, saturator, compressed-air quality, pressure regulation, collector locations and controllable fallout performance.
Temperature and Solution
Chamber/saturator range, control tolerances, solution tank capacity, level protection, pH measurement and wetted materials.
Records and Alarms
Controller, timer, temperature records, alarms and data export. Spray fallout and pH may still require manual measurement unless automatic systems are explicitly included.
Five Controls Behind a Valid Salt Fog Test
Prepare the Specimens
Follow the product method for cleaning, masking, scribing, orientation and initial measurements.
Prepare the Solution
Use water and salt of the required purity. Prepare concentration and acidity according to the selected current standard.
Condition the Chamber
Stabilize temperatures and air supply; verify collectors are positioned within the defined usable workspace.
Verify the Environment
Measure collected-fog volume, pH and other required conditions at the specified intervals and take corrective action when outside limits.
Evaluate by Product Spec
Use the required method for rust, blistering, scribe creep, mass loss or coating defects. Report interruptions and observations.
A Standard Salt Spray Chamber Is Not Automatically a CCT Chamber
Modern automotive cyclic corrosion tests can require fog, high humidity, controlled drying, ambient transitions and precisely programmed repeats. A continuous salt fog cabinet may not provide those conditions.
ASTM G85 Mapping
Do not call Annex A3 “Prohesion.” A3 is the seawater acidified cyclic test (SWAAT). Prohesion is commonly associated with the dilute-electrolyte cyclic fog/dry procedure in Annex A5. Confirm the current edition and exact annex.
Dedicated Cyclic Equipment
For programmable salt fog, humidity and dry stages, use a verified cyclic salt spray chamber configuration rather than assuming optional controller software is sufficient.
Choose Capacity from the Specimen, Not Liters Alone
- Largest specimen dimensions and orientation
- Quantity and spacing per batch
- Required rack or custom fixture
- Distance from atomizer and fog collectors
- Solution demand and unattended duration
- Compressed air, exhaust and drainage
- NSS only versus AASS/CASS segregation
- Calibration and acceptance documentation
Prevent Overloading
Specimens must not shield one another, block fog flow or allow runoff to contaminate other samples. Send a loading drawing with the inquiry. For a confirmed compact-capacity product, see the 160 salt fog test chamber; for oversized products, review the large salt spray chamber guide.
Keep Chloride Away from Vulnerable Components
Corrosion-Resistant Test Space
Wetted surfaces, racks, solution lines and fasteners should be compatible with the chosen solution and must not contaminate specimens. Confirm PP/FRP thickness and construction on the approved drawing.
Routine Control
Inspect and clean nozzles, collectors, saturator, solution tank, seals and drains on a documented schedule. Rinse thoroughly when switching solutions; dedicated circuits may be preferable for CASS.
Compressed Air and Water
Oil, particles or unsuitable water can change the test environment. Specify filtration, water purity, inlet pressure and utility monitoring.
Waste and Operator Safety
Acidic or copper-containing waste is not equivalent to plain saline solution. Provide ventilation, PPE, eyewash and disposal procedures based on local requirements and the chemicals used.
Salt Spray Corrosion Test Chamber FAQs
What is an ASTM B117 salt spray chamber?
It is apparatus operated to create and maintain the continuous salt-fog environment described by ASTM B117 for relative comparison of metals and coated metals.
Does ASTM B117 specify how many hours a product must pass?
No. The product or customer specification defines specimens, duration and acceptance criteria.
Can salt spray hours predict outdoor service life?
Not reliably as a universal conversion. Use salt spray for comparative quality data and corroborate with relevant field or cyclic exposure when needed.
Can one chamber run NSS, AASS and CASS?
Potentially, if its temperature range, materials, solution system and cleaning/segregation procedures support them. CASS contamination may justify dedicated equipment.
Is ASTM G85 A3 the Prohesion test?
No. A3 is associated with SWAAT. Prohesion is commonly the Annex A5 dilute-electrolyte cyclic fog/dry procedure.
Can this chamber run automotive cyclic corrosion tests?
Only if it has verified fog, humidity, dry, transition and programming performance for the exact method. A continuous B117 cabinet is not automatically suitable.
What causes inconsistent salt spray results?
Common causes include specimen loading, nozzle contamination, air quality, unstable temperatures, solution errors, collector placement and poor maintenance.
What information is needed for selection?
Send the standard/edition, test mode, specimen drawing and quantity, exposure duration, acceptance method, utility conditions, records and calibration requirements.
Specify the Test Mode and Loading Plan
Send DERUI the applicable standard and edition, NSS/AASS/CASS mode, specimen dimensions, quantity, duration, evaluation method and laboratory utilities. We will verify chamber capacity and configuration.
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