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Needle Flame Tester:

The needle flame tester is suitable for use in electrical and electronic equipment, including lighting, low-voltage electrical appliances, household appliances, machine tools, motors, power tools, electronic instruments, electrical meters, information technology equipment, electrical utility equipment, electrical connectors, accessories, and their components, as well as in production and quality inspection departments. It is also suitable for use in the insulation materials, engineering plastics, and other solid combustible materials industries.

Standardized Operation Process Analysis

1. Pre-Test System Preparation

Before testing, ensure the laboratory environment meets standard requirements. The temperature should be strictly controlled within the range of 23 ± 2°C, and the relative humidity should be maintained between 45% and 75%. The laboratory must be equipped with an effective exhaust system, but the exhaust speed must not exceed 0.2 m/s to avoid affecting flame stability.

Equipment calibration is critical to ensuring test accuracy. First, use a dedicated gauge to calibrate the flame height to ensure it is precisely controlled within the standard range of 12 ± 1 mm. Regarding temperature calibration, it is recommended to verify the thermocouples quarterly using a standard temperature source to ensure accurate temperature measurement.

Specimen preparation requires special attention. The standard sample size should be no less than 100 mm x 100 mm, and at least three replicate samples should be prepared for each test. All samples must remain in the test environment for at least 24 hours to eliminate the effects of environmental stress on the test results.

2. Key Controls During the Test

At the beginning of the test, the equipment must be preheated for 15 minutes to achieve stable conditions. Ensure the sample is securely mounted to prevent movement during testing. Pay special attention to flame position calibration, ensuring the flame maintains a standard 45° or perpendicular angle with the sample surface.

During the test, three key indicators should be observed: First, the burning duration, accurately recording the entire time from flame contact to sample self-extinguishing. Second, closely observe for the generation of burning drips and whether these drips ignite the underlying standard gauze. Finally, accurately measure the sample’s burn length with an accuracy of 0.5mm.

3. Data Recording Requirements

Complete data recording should include key parameters such as the precise time of flame application, sample self-extinguishing time, and combustion spread. It is recommended to use a high-definition camera for full recording, with a frame rate of at least 30 fps. Where possible, an electronic data acquisition system is recommended to avoid errors caused by manual recording.

Typical Troubleshooting and Solutions

1. Common Flame System Issues

A yellow and unstable flame is usually caused by insufficient gas purity or a clogged nozzle. The solution is to switch to high-purity propane fuel and clean the nozzle with a dedicated needle. If significant fluctuations in flame height are observed, check the pressure setting of the pressure reducing valve and adjust it to the standard range of 0.1±0.01 MPa.

Automatic ignition system failures are often caused by carbon deposits on the ignition electrodes. The solution is to clean the electrodes with alcohol wipes and ensure that the electrode spacing remains within the standard range of 3-5 mm. It is important to note that frequent ignition failures may indicate a leak in the gas pipeline, which requires a systematic inspection.

2. Analysis of Abnormal Test Data

When test results fluctuate abnormally, the first step is to investigate the sample. For example, a laboratory discovered large data dispersion when testing PP material. This was attributed to uneven sample thickness. Adjusting the thickness to 1.0±0.1 mm resolved the issue. Environmental factors are also important. One laboratory experienced test results that deviated by more than 15% from those of the certification body due to excessive humidity. These results were restored to normal after installing dehumidification equipment.

3. Safety Emergency Procedures

In the event of an emergency, immediately press the emergency stop button to shut off the gas supply. Burning samples should be covered with a dedicated fire blanket; water-based fire extinguishing agents are strictly prohibited. Laboratories must be equipped with professional protective equipment such as flame-retardant gloves and auto-darkening welding masks that meet EN407 standards, and the effectiveness of CO2 fire extinguishers must be regularly checked.

 System Maintenance and Care Strategies

As a precision testing device, the needle flame tester requires proper operation and regular maintenance to ensure proper function and accurate test results.

Operation requires a rigorous series of steps. First, prepare the test sample. Place the material to be tested on the test bench, ensuring the sample surface is flat, smooth, and free of impurities and protrusions to ensure test accuracy. Next, connect the power cord of the needle flame tester to an appropriate electrical outlet and ensure a good ground connection to prevent electric shock. Then, adjust test parameters such as test temperature, time, and gas flow rate according to test requirements. Next, place the needle on the specimen and adjust its height and angle to ensure good contact with the specimen surface, ensuring accurate flame application. After igniting the needle, begin the test. Observe the flame spread and sample combustion during the test, and record the relevant data. The test ends when the set time is reached or when the sample extinguishes. Finally, clean up the test site, remove the test sample, and keep it tidy.

Regular cleaning is essential for maintenance. The tester’s casing, combustion chamber, and other components should be cleaned regularly to remove dust, dirt, and debris. Use a clean, damp cloth to wipe, avoiding the use of corrosive cleaning agents to prevent damage. The equipment should also be calibrated regularly. Calibration should be performed annually by a professional testing company. After each startup, perform a check to ensure the equipment is free of visible damage and abnormalities. Additionally, check for loose screws and tighten them promptly. Clamps should be coated with rust-proof oil and stored. Regularly check the chain and tighten any looseness.

Inspection and maintenance of the gas source are also crucial. At the beginning of each test, adjust the flame control valve to its minimum setting to prevent uncontrolled ignition. After the test, remove the gas tank and inspect the gas circuit regularly for leaks, such as leaks in the joints and gas pipes, to prevent accidents and affect the needle flame. For the next test, wait until the temperature drops below 50°C before repeating the above steps.