How does a spray chamber work?

Salt spray test chambers use salt spray corrosion to test the corrosion resistance reliability of individual samples. Salt spray refers to a diffuse system composed of tiny salt-containing droplets in the atmosphere, and is one type of artificial environmental protection system. Many companies need to simulate the destructive effects of marine climates on their products, hence the development of salt spray test chambers.

Test Principle

Corrosive solutions are sprayed into a mist by compressed air, and this mist surrounds the test sample inside the test chamber.

The test can be continuous or cyclic.

The corrosion resistance of each sample is defined as the time it takes for corrosion to occur; the longer the time, the better the corrosion resistance.

Salt Spray Corrosion Test Chamber Technical Data

Operating Procedures

1. First, connect the power supply to the salt spray chamber and the air compressor, and connect the air compressor hose.

2. Add purified water or distilled water to the chamber and the water inlet on the back of the chamber until the low water level indicator on the panel goes out; otherwise, it will not operate normally.

3. After connecting the drain pipe and exhaust pipe, as shown on the previous page, the indicator pointing to the left indicates "open".

4. Fill the isolation water tank to the level of the pad to prevent salt spray leakage.

5. Pour the saline solution into the saline replenishment bottle; the system will automatically fill the saline solution into the laboratory spray tower, allowing the chemical solution to flow into the saline spray tower.

6. Add water to the wet bulb cup. Cover the wet bulb thermometer with gauze, placing the end of the gauze inside the wet bulb cup.

7. Place the test piece or sample on the shelf: the placement angle should be according to the required standard specifications. For example, a standard test piece of 130×70 (mm) can be placed at a 15-degree or 30-degree angle.

8. Press the power button and operate the control panel to preheat to the set temperature. Note: The test cover must be closed and handled carefully to avoid breakage.

9. Press the timer button to start the timer according to the set time.

10. After the test, turn off all switches in sequence.

11. If any abnormal phenomena occur during the test, please refer to the functional malfunction judgment table for handling.

Placement Method

1. Salt spray corrosion test samples should generally not be laid flat. Salt spray standards require that the test surface of the sample should be at an angle of 15°~30° to the vertical direction, and preferably 20°. For irregular samples (such as entire workpieces), this requirement should be as close as possible.

2. Place the test sample inside the salt spray test chamber with the test surface facing upwards. Allow the salt spray generated during the test to freely settle and deposit on the test surface of the sample. The salt spray should not be directly sprayed onto the test surface of the sample.

3. Test samples in the salt spray corrosion test chamber can be placed on different horizontal surfaces inside the chamber, but they must not touch the chamber body, and even more so, they must not touch each other. The distance between test samples should not affect the free fall of salt spray onto the test surface, and salt spray droplets accumulating on one test sample must not drip onto other test samples.

4. The sample holders in the salt spray corrosion test chamber are made of materials resistant to salt spray, acid, and alkali corrosion, such as glass or plastic. If samples need to be suspended on the holder, the suspension material cannot be metal; generally, non-metallic materials such as cotton fiber, synthetic fiber, or other insulating materials are used.

Abnormal Phenomena

When using a salt spray test chamber for product testing, it typically operates continuously for one or even several months. The harsh environment can easily cause various malfunctions, both major and minor, to occur. To help users quickly resolve salt spray test chamber malfunctions and continue conducting salt spray aging tests smoothly, Shangce has provided a detailed introduction to some common malfunctions and their solutions.

I. Causes and Troubleshooting of Salt Spray Test Chamber Spray Malfunctions:

Insufficient Spray Volume:

1. Spray regulator set too low. Adjust the spray regulator to a higher setting.

2. Glass filter in the preheating tank is clogged. Clean the glass filter.

3. Check if the nozzles are partially blocked. If blocked, remove the debris.

4. Pressure setting too low. Adjust the pressure regulating valve.

No Spray:

1. Air compressor not running. Turn on the air compressor and check if the air compressor's air pipe connections are correct.

2. Check if the pressure regulating valve is open. Adjust it to the normal pressure value.

3. Check if the nozzles are clogged. Nozzles are consumables; they generally wear out after 1500 hours of use and should be replaced.

4. Check if the spray switch is damaged. If damaged, replace the switch.

5. Check if the spray solenoid valve is broken. If there is air intake but no air output, remove the solenoid valve and clean it. If the coil is burnt out, replace the matching solenoid valve coil; otherwise, replace the entire solenoid valve.

6. Check if there is saline solution. If not, add an appropriate amount.

II. Causes and solutions for heating malfunctions in the salt spray test chamber:

Salt spray test chamber cannot heat:

1. The heating solid-state relay has no output; replace the solid-state relay.

2. The instrument has no output; replace the instrument.

3. The heating element is damaged; check the heating element resistance. If it is abnormal, replace it.

4. Water shortage causes heating shielding; check if the water level is normal and if the float is malfunctioning.

5. Over-temperature protection malfunction; adjust the protection temperature value. If the problem persists, replace the over-temperature protection device.

Salt spray test chamber heating temperature is abnormal:

1. The chamber temperature controller is set too low; set the temperature controller to the required value. Temperature

2. The laboratory safety protection switch is set too low. Set the safety protection switch to the required temperature.

3. The saturation tank temperature controller is set too low. Set the temperature controller to the required temperature.

4. The saturation tank safety protection switch is set too low. Set the safety protection switch to the required temperature.

III. Salt spray test chamber instruments have no display:

1. Check if the salt spray test chamber has power. If there is no power, please have a professional electrician check.

2. Check if the power switch is damaged. If damaged, please replace the power switch.

3. Check if the power circuit breaker is damaged. If damaged, please replace the circuit breaker.

4. Check if there is power at the instrument power terminals. If there is power, the instrument is damaged and needs to be replaced.

5. Check if there are black marks on the salt spray chamber instrument power terminals. If there are black marks, the instrument may be burnt out and needs to be replaced.

Operating Instructions

1. The salt spray test chamber should be placed approximately 50cm away from the wall at the back. Sufficient maintenance space should be maintained on both sides.

2. Please install an additional fuse-less switch or knife switch before the main power cord.

3. The exhaust pipe can be extended outdoors using a 50mm diameter PVC rigid pipe. Note that the exhaust pipe should be installed with a straight downward slope from the pipe opening.

4. The salt spray test chamber should be installed away from direct sunlight to avoid affecting testing conditions.

5. The chamber is made of PVC plastic. Prevent impacts. Do not exceed the standard test temperature range to avoid deformation due to overheating.

6. Over-temperature indicator light: When the over-temperature indicator light is on, the test chamber is protected against overheating. Please check if the temperature setting on the temperature instrument is too high or the temperature control setting is too low.

7. Low water level indicator light: When the low water level indicator light is on, the test chamber or saturator is protected against water shortage and will cut off the operating power. At this time, check if the test chamber or saturator is leaking.

VIII. End Indicator Light: This light indicates the test is complete.

IX. Salt Spray Test Chamber Power Supply: 380V/220V 50Hz

Installation Precautions

I. Salt Spray Test Chamber Water Supply System Installation

1. Water Quality Requirements: Purified water (other water containing minerals or impurities cannot be used). Industrial water and tap water can also be used, but a filter must be installed (the pH of the filtered water should be between 6.5 and 7.2).

2. Pressure Requirements: Ensure normal water supply; the water pressure must be maintained between 1 and 3 kg.

3. Interface Requirements: The equipment's water supply port must be connected with a flexible hose and secured with a sealing ring to prevent leakage.

II. Salt Spray Test Chamber Power Supply System Requirements

1. Power Supply: Single-phase AC 220V 50Hz

2. Current: Max 15 A

3. Protection Switch: An independent leakage protection switch needs to be installed.

III. Salt Spray Test Chamber Air Intake System Installation

1. Pressure Requirements: Air pressure ≥ 3 kg, clean and dry air compressor or air supply pipe.

2. Interface Requirements: Use quick connectors for easy disassembly and maintenance.

3. Air Supply Time: Ensure uninterrupted air supply during normal equipment operation.

IV. Salt Spray Test Chamber Exhaust System Requirements

1. Material: PVC polyethylene material (corrosion resistant) is required.

2. Interface: Connect the equipment exhaust port with a rigid pipe and seal it tightly with sealant to prevent leakage.

3. Drilling Requirements: The wall opening height should be slightly higher than the exhaust port to ensure that condensed gas flows back into the test chamber.

V. Salt Spray Test Chamber Drainage System Installation

1. Drilling Requirements: The equipment uses natural drainage; the wall opening height should be lower than the drain outlet to ensure normal drainage.

2. Interface Requirements: The equipment drain outlet can be connected with a flexible hose or rigid pipe and then secured with a sealing ring to prevent leakage.