Electric scooter inspection method of penetration testing

Electric scooter inspection method of penetration testing
In the manufacturing, use and maintenance of electric scooters, it is crucial to ensure their quality and safety. As an effective non-destructive testing method, penetration testing plays an important role in electric scooter inspection. This article will explore in depth various aspects of penetration testing for electric scooters, including detection principles, methods, steps, application examples, advantages and limitations, etc., aiming to help readers fully understand this detection technology.

1. Overview of penetration testing
Penetrating testing, also known as penetrant flaw detection, is a non-destructive testing method for detecting open defects on the surface of materials. Its basic principle is to use the capillary action of the penetrant to penetrate into the open defects such as tiny cracks and pores on the surface of the material. After cleaning and removing the excess penetrant on the surface, the developer is applied to make the penetrant remaining in the defect adsorbed to the surface, thereby forming an enlarged and colored defect display, which is convenient for the inspector to observe and judge the existence of defects.
Penetrant testing has the advantages of simple operation, low cost, high detection sensitivity, and wide application range. It can effectively detect various minor defects on the surface of electric scooter parts, such as cracks, sand holes, pores, etc. in the frame, handlebars, wheels, brake system and other parts, which is of great significance for ensuring the quality and safety of electric scooters.

2. Principle of penetrant testing
Penetrating testing is mainly based on capillary phenomenon and wetting. When the penetrant is applied to the surface to be tested, it will spread on the surface due to wetting. At the same time, under the action of capillary force, the penetrant will gradually penetrate into the defects of the surface opening. The penetration ability of the penetrant is related to the chemical properties, viscosity, surface tension of the penetrant, and the size and shape of the defect.
Generally speaking, the lower the viscosity and the smaller the surface tension of the penetrant, the stronger its penetration ability and the more effective it can penetrate into tiny defects. The width, depth and shape of the defect opening will also affect the penetration effect of the penetrant. Wider and shallower defects may be more easily filled by the penetrant, while small and deep cracks require longer time and higher sensitivity to detect.

3. Classification and characteristics of penetrant detection agents
(I) Penetrants
According to the dyes contained in the penetrants and the observation conditions of the workpiece to be inspected, penetrants can be divided into two categories: color penetrants and fluorescent penetrants.
Color penetrants: Contains brightly colored dyes that can form a clearly visible defect display under normal white light. Its advantages are simple detection equipment, only ordinary light sources and naked eye observation are required, and the cost is low; the disadvantage is that the detection sensitivity is relatively low, and the display of shallower or narrower defects is not obvious enough. It is usually used to detect defects with larger and more obvious surface openings.
Fluorescent penetrants: Contains dyes that can produce fluorescence, which will produce bright fluorescence under ultraviolet irradiation, thereby obtaining higher detection sensitivity. Fluorescent penetrants can detect smaller and shallower surface opening defects and are suitable for occasions with higher detection sensitivity requirements. However, fluorescent penetrant testing requires equipment such as ultraviolet lamps and darkrooms, and the testing cost is relatively high, and the testing environment requirements are relatively strict.
(II) Removers
There are mainly solvent-based removers and emulsified removers used to remove excess penetrants from the surface to be tested.
Solvent-based removers: can dissolve the penetrant and separate it from the surface to be tested. Its advantage is that it has a good removal effect and can quickly and effectively remove excess penetrants on the surface; its disadvantage is that improper use may cause the penetrant to be removed together with the penetrant in the defect, thereby affecting the accuracy of the test results, and the solvent-based remover is highly volatile, which poses certain safety hazards and environmental pollution problems.
Emulsified removers: can emulsify the penetrant to form a water-soluble mixture, which is easy to remove with water. The removal process of emulsified removers is relatively mild, and it is not easy to excessively remove the penetrant in the defect, and the detection reliability is high, but its removal effect may be affected by many factors, such as emulsification time, water temperature, etc., and the removal process parameters need to be strictly controlled.
(III) Developer
The function of the developer is to adsorb the penetrant remaining in the defect to the surface to form a clear and visible defect display image. The developer is usually a white powder with high contrast and adsorption performance. According to the form of use of the developer, it can be divided into dry powder developer, solvent suspension developer and water-soluble developer.
Dry powder developer: It is applied to the surface to be inspected in a dry powder state. It has high adsorption capacity and imaging sensitivity, and is suitable for detecting workpieces with large surface roughness. However, dry powder developers may generate dust and pollute the environment during use, and the imaging effect may not be uniform for workpieces with smoother surfaces.
Solvent suspension developer: The developer powder is suspended in an organic solvent and applied to the surface to be inspected by spraying or dipping. Its advantage is that it can evenly cover the surface to be inspected and has a good imaging effect, especially for workpieces with smoother surfaces; but the organic solvent in the solvent suspension developer is volatile and flammable, and attention should be paid to ventilation and fire safety when using it.
Water-soluble developer: It uses water as the suspension medium, has the advantages of no pollution, non-toxicity, non-flammability, etc., and is safe and convenient to use. Its developing performance is equivalent to that of solvent suspension developer, but it may be affected by water quality, such as impurities and hardness in the water, and the water quality needs to be properly treated and controlled.

4. Steps for penetration testing of electric scooters
(I) Preparation before testing
Surface cleaning
The surfaces of electric scooter parts to be tested must be thoroughly cleaned to remove oil, dust, rust, oxide scale, paint and other dirt. Because these impurities will affect the wetting and penetration effect of the penetrant, and may even cover up surface defects, resulting in inaccurate test results.
The cleaning method can be selected according to the specific situation, such as using solvent cleaning, alkali cleaning, mechanical grinding, sandblasting, etc. For example, for parts with more oil on the surface, organic solvents such as gasoline and acetone can be used for wiping and cleaning; for parts with rust and oxide scale, mechanical grinding or sandblasting can be performed first until the metallic luster is exposed, and then solvent cleaning can be performed to ensure that the surface is clean.
Select the appropriate penetrant
Select the appropriate penetrant, remover and developer according to the material, surface condition, defect type and detection sensitivity requirements of the electric scooter parts.
For example, for the rough surface of the frame welding part, you can choose a colored penetrant with slightly higher viscosity and stronger penetration ability, combined with a solvent-based remover and a dry powder developer; for handlebars, wheels and other parts with smooth surfaces, if you need to detect tiny surface cracks, you can choose a fluorescent penetrant, combined with an emulsified remover and a solvent suspension developer or a water-soluble developer to obtain higher detection sensitivity.
(II) Penetration
Apply the selected penetrant evenly to the surface to be inspected, ensuring that the entire inspected area is covered by the penetrant. The application method can be spraying, brushing, dipping, etc., and it can be selected according to the shape and size of the electric scooter parts and the conditions of the inspection site.
The spraying method is suitable for relatively flat and large parts, such as frames, and can quickly and evenly cover the surface to be inspected with penetrants; the brushing method is suitable for local areas or parts with complex shapes, such as the connection between the handlebar and the frame, and can better control the amount and range of penetrant application; the dipping method is mainly used for small parts, such as some small parts of the brake system, which can completely immerse the parts in the penetrant to ensure that the penetrant fully penetrates the surface defects.
After the penetrant is applied, it is necessary to maintain a certain penetration time, generally 5-15 minutes. The specific time should be determined according to factors such as the type of penetrant, the nature of the material to be inspected, and the size of the defect to be detected. During this period, the penetrant will gradually penetrate into the defects of the surface opening.
For example, for larger defects or penetrants with strong penetration ability, the penetration time can be appropriately shortened; while for small defects or penetrants with relatively weak penetration ability, the penetration time needs to be extended to ensure that the penetrant can fully penetrate into the depth of the defect.
(III) Removal of excess penetrant
After the penetration time is over, the excess penetrant on the surface to be inspected needs to be removed, which is a key step in the penetration detection process. The removal method depends on the type of remover selected.
If a solvent remover is used, first use a clean cloth or paper to dip a small amount of remover, gently wipe the surface to be inspected, and gradually remove the excess penetrant on the surface from the edge to the center. Note that the wiping action should be gentle to avoid excessive wiping, which will cause the penetrant in the defect to be removed. Then, use a clean cloth or paper to dip in the solvent for a second wipe until there is no residual penetrant on the surface. Finally, let the surface to be inspected dry naturally or blow it dry with compressed air.
If an emulsified remover is used, first spray or apply the emulsifier on the surface to be inspected, and wait for a certain period of time (emulsification time) to allow the emulsifier and penetrant to fully emulsify and form a water-soluble mixture. The emulsification time is generally 1-5 minutes, and the specific time should be controlled according to the instructions of the emulsifier. After that, rinse with water at a temperature not exceeding 40°C until there is no residual penetrant and emulsifier on the surface, and then dry the surface to be inspected.
In the process of removing excess penetrant, the removal time and strength should be strictly controlled to avoid excessive or incomplete removal. Incomplete removal will cause the background to be too dirty, interfering with the observation and judgment of defects; while excessive removal will also take away the penetrant in the defect, affecting the accuracy of the test results.
(IV) Drying
After removing the excess penetrant, the surface to be inspected needs to be dried. Drying methods usually include natural drying, hot air drying or the use of desiccant. Natural drying takes a long time, generally takes 5-10 minutes, and is suitable for situations where the drying time is not required; hot air drying can speed up the drying speed, but it is necessary to control the temperature of the hot air, generally not exceeding 50℃, so as not to damage the inspected parts or affect the subsequent development effect; special desiccant can also be used for drying, but it is necessary to ensure that the desiccant will not have adverse effects on the inspected surface and the subsequent detection process.
The inspected surface after drying should be free of moisture, oil, dust and other impurities to ensure that the developer can be evenly adsorbed on the surface and the penetrant in the defect can be fully displayed.
(V) Development
Apply the developer evenly to the inspected surface after drying. The developer will absorb the penetrant remaining in the defect and form a clear and visible defect display image on the surface.
The method of applying the developer can be selected according to the type of developer. For example, dry powder developer can be applied by electrostatic spraying or compressed air blowing to evenly cover the inspected surface; solvent suspension developer and water-soluble developer can be applied by spraying or dipping. When applying the developer, pay attention to maintaining a certain distance and uniform coating thickness to avoid the developer being too thick or too thin to affect the test results.
The development time is generally 5-10 minutes, and the specific time should be determined according to the performance of the developer and the requirements of the instructions. During this period, the developer will react with the penetrant in the defect to form a clear defect display. The imaging sensitivity and contrast of the developer are crucial to the detection and identification of defects. High-sensitivity developers can show tiny defects more clearly.
VI) Observation and evaluation
Within the specified time after imaging, observe the inspected surface to identify and evaluate the defect display. Observation should be carried out in a suitable environment. For color penetration testing, it should be observed under sufficient white light; for fluorescent penetration testing, it is necessary to use ultraviolet light in a dark room for observation.
During the observation process, the inspector should carefully identify the shape, size, location and distribution of the defects, and evaluate and classify the defects according to relevant standards and specifications. For example, for crack defects on the surface of the frame, it can be determined whether it is qualified according to its length, depth and other parameters, according to the corresponding welding joint quality standards or component acceptance standards.
The evaluation of defect display usually includes the following aspects:
Defect type: According to the shape and characteristics of the defect, it is determined whether it is a crack, pore, inclusion or other type of defect. For example, cracks usually appear as slender, continuous or discontinuous linear displays, while pores are mostly circular or elliptical displays.
Defect size: Measure the dimensional parameters such as length, width and area of ​​the defect display to evaluate the severity of the defect. Generally speaking, when the defect size exceeds a certain limit, it will affect the performance and safety of the parts and components, and corresponding treatment or replacement is required.
Defect location: Determine the specific location of the defect on the parts and components, especially for defects in some key parts, such as the stress concentration area of ​​the frame, the brake components of the brake system, etc., even if the defect size is small, it may pose a greater threat to the safety of use and needs to be paid special attention.
Defect quantity and distribution: Count the number of defects in a certain area and the distribution of defects, such as whether they are densely distributed and whether they are regular. A large number of densely distributed defects may reduce the overall strength and reliability of the parts and components, affecting the normal use of the electric scooter.
(VII) Post-processing
After the penetration test is completed, the electric scooter parts that have passed the test need to be post-processed to restore their surface state and performance. Post-processing mainly includes steps such as removing the developer and protective treatment.
The developer can be removed by wiping or cleaning with a suitable solvent or detergent to ensure that there is no residual developer on the surface. Afterwards, according to the use requirements of the parts, protective treatment is carried out, such as coating with anti-rust oil, grease, etc., to prevent the parts from rusting or wearing during use and extend their service life.
For parts that fail the inspection, corresponding repair measures or scrapping should be taken according to the nature and severity of the defects. For example, for some surface crack defects, if the cracks are shallow and do not exceed the allowable repair range of the material, they can be repaired by grinding, welding repair, etc., and re-perform penetration testing to ensure that the defects are completely eliminated; and for parts that are seriously exceeded and cannot be repaired, they should be scrapped to avoid safety accidents during use.

5. Application Examples of Penetrant Testing in Electric Scooter Testing
(I) Frame Testing
The frame is one of the core components of electric scooters and is subject to various loads and stresses. Its quality is directly related to the safety and service life of the entire vehicle. In the production and manufacturing process of the frame, welding quality is one of the key factors affecting the performance of the frame. Welding parts are prone to defects such as cracks, unfused parts, and pores.
By performing penetrant testing on the welding parts of the frame, these surface opening defects can be effectively discovered. For example, in the quality inspection process of a certain electric scooter manufacturer, a batch of newly produced frames were subjected to fluorescent penetrant testing. The inspectors followed the standard penetrant testing steps to perform surface cleaning, penetration, removal of excess penetrant, drying, imaging, and observation on the welding parts of the frame. Under ultraviolet irradiation, bright fluorescent displays were found at the welding joints of individual frames, which were assessed as crack defects. The company promptly repaired or scrapped these unqualified frames, effectively preventing unqualified products from entering the market and ensuring the safety of consumers.
(II) Brake system testing
The brake system is an important guarantee for the safe operation of electric scooters, and the performance and quality of its components are crucial. During long-term use, the brake disc, brake caliper and other components of the brake system may develop cracks and other defects due to mechanical fatigue, thermal fatigue and other factors. These defects may cause brake failure and cause serious safety accidents.
Regular penetration testing of brake system components can timely detect potential crack defects. Taking the brake disc as an example, when conducting penetration testing on its surface, first clean the oil, dust and other dirt on its surface, then apply a coloring penetrant. After a certain period of penetration, remove the excess penetrant on the surface, and then apply a developer. Under white light, if there are cracks on the surface of the brake disc, a clear red line display will appear. The inspector can evaluate the defects according to the display and replace the cracked brake disc in time to ensure the reliability and safety of the brake system.
(III) Wheel detection
The wheels of electric scooters are subjected to greater impact and friction during driving, and are prone to surface cracks, holes and other defects. Especially for some wheels made of aluminum alloy or other lightweight materials, their surface defects may gradually expand during use, causing the wheel to break and endanger driving safety.
In the production and use of wheels, it is of great significance to use penetration testing to control quality and monitor safety. By conducting penetration testing on the wheel hub, rim and other parts of the wheel, subtle defects on the surface can be found in time. For example, when an electric scooter repair factory was overhauling a batch of old wheels, it used the color penetration testing method and found that there were small crack defects in the wheel hub of some wheels. These wheels were replaced in time, avoiding safety accidents caused by wheel failures and ensuring the safety of users' travel.

6. Advantages of penetration testing for electric scooters

High sensitivity: It can detect tiny opening defects on the surface of electric scooter parts, such as cracks with a width of only microns, which provides a strong guarantee for product quality control and safety assessment.

Wide detection range: It is suitable for surface testing of various materials of electric scooters. Whether it is metal or non-metal materials, as long as the surface has a certain degree of roughness and cleanliness, effective penetration testing can be carried out. It covers the detection of multiple key components such as frames, handlebars, wheels, brake systems, motor housings, etc., to fully guarantee the quality and safety performance of electric scooters.
Easy to operate: The equipment and instruments for penetration testing are relatively simple, and no large and complex testing equipment is required. The operation process is easy to master. Trained testers can conduct rapid testing on site or in the workshop, which is convenient for batch testing and quality screening of electric scooter parts.
Low cost: Compared with some other advanced non-destructive testing technologies, such as ultrasonic testing and radiographic testing, the cost of penetration testing is relatively low, including the cost of detection agents, equipment investment, and consumables during the testing process. This is highly economical and feasible in terms of quality control for products such as electric scooters with large production and fierce market competition.
Intuitive: The test results are intuitive, and the shape, size and position of the defects can be directly observed by the naked eye or under ultraviolet light. The test results are easy to record and analyze, which is convenient for testers to make judgments and decisions quickly, deal with unqualified parts in a timely manner, and improve production efficiency and product quality control.

VII. Limitations of penetration testing of electric scooters
Only surface opening defects can be detected: Penetrant testing can only detect defects that are open on the surface of the material, and internal defects or closed defects cannot be effectively detected. Therefore, when evaluating the overall quality of electric scooter parts, it is necessary to combine other non-destructive testing methods, such as ultrasonic testing, radiographic testing, etc., to fully understand the internal structure and defects of the parts.
The test results are easily affected by subjective factors: The observation and evaluation process of penetration testing mainly relies on the visual judgment of the test personnel. The accuracy and reliability of the test results are affected to a certain extent by subjective factors such as the experience, vision, and working status of the test personnel. Different testers may produce different evaluation results for the display of the same defect, which may lead to instability and uncertainty in quality control.
High requirements for the cleanliness of the inspected surface: If there are dirt such as oil, rust, and scale on the inspected surface, even after cleaning, it may affect the penetration and imaging effect of the penetrant, resulting in missed or misdetected defects. Therefore, the surface cleaning quality needs to be strictly controlled before testing, which increases the preparation time and workload of the test.
Limited ability to quantitatively analyze defects: Penetrant testing mainly conducts qualitative analysis based on the characteristics of the shape, size, and position of the defect display. The measurement accuracy of quantitative parameters such as the depth and volume of the defect is low, and it is difficult to accurately evaluate the actual impact of the defect on the performance of the component. In some occasions where precise quantitative analysis of defects is required, such as evaluating the remaining life of cracks, penetration testing is difficult to meet the requirements.
Toxicity and flammability of detection agents: Some penetration detection agents contain organic solvents, which have certain toxicity, flammability and volatility. During use, they may pose a threat to the health and safety of the detection personnel and also cause pollution to the environment. Therefore, when using these detection agents, corresponding protective measures need to be taken, such as wearing protective gloves, masks, goggles, etc., ensuring that the workplace is well ventilated, and complying with relevant safety operating procedures and environmental protection requirements.

7. Quality control of penetration testing of electric scooters
In order to ensure the accuracy and reliability of penetration testing results and improve the quality inspection level of electric scooters, it is necessary to strengthen the quality control of penetration testing from the following aspects:
(I) Training and qualification certification of detection personnel
Penetration testing personnel should have corresponding professional knowledge and skills training, be familiar with the principles, methods, steps and standards of penetration testing, master the performance and use of different detection agents, and the identification and evaluation skills of various defect display characteristics.
The inspectors need to pass the professional qualification certification examination and obtain the corresponding non-destructive testing qualification certificate before they can engage in penetration testing of electric scooters. Regularly participate in refresher training and continuing education, constantly update knowledge and skills, and improve the level of testing and quality awareness.
(II) Management of testing equipment and reagents
Establish and improve the management system of testing equipment, regularly maintain, maintain and calibrate the penetration testing equipment to ensure the normal operation of the equipment and the accuracy of the testing parameters. For example, the irradiance of the ultraviolet lamp should be measured and calibrated regularly using a radiometer to ensure that it works within the specified irradiance range to meet the requirements of fluorescent penetration testing.
Strictly control the quality of the penetration test agent, select the appropriate test agent in accordance with relevant standards and specifications, and test and verify the performance of the test agent before use, such as the fluorescence brightness, viscosity, surface tension and other indicators of the penetrant should meet the requirements. At the same time, the test agent should be properly stored to prevent it from being contaminated, deteriorated or expired, and ensure the quality of the test agent is stable and reliable.
(III) Standardization of testing process
Develop detailed penetration testing process documents, clearly specify the testing methods, steps, process parameters (such as penetration time, emulsification time, drying temperature, etc.) and defect assessment standards of each component of the electric scooter, and ensure the standardization and standardization of the testing process.
Testers should strictly follow the requirements of the process documents to avoid the influence of human factors on the test results. During the test process, all test parameters and results should be recorded truthfully, and test files should be established to facilitate quality traceability and data analysis.
(IV) Control of environmental conditions
The environmental conditions of penetration testing have an important impact on the test results. According to the requirements of the test method and the test agent, the temperature, humidity, light and other environmental factors of the test site should be controlled. For example, fluorescent penetration testing needs to be carried out in a dark room, and the ambient light should meet the observation requirements under ultraviolet irradiation to avoid interference from external light; while color penetration testing needs to be observed under sufficient white light to ensure that the defects are clearly visible.
The temperature and humidity of the test environment should be kept as stable as possible and meet the use temperature range and process requirements of the test agent. Generally speaking, the ambient temperature of penetration testing should be controlled between 10-50℃, and the relative humidity should be between 30%-70%. In high temperature and high humidity or low temperature and low humidity environments, the performance of the penetrant and the accuracy of the test results may be affected, and corresponding temperature and humidity adjustment measures need to be taken.
(V) Quality Audit and Continuous Improvement
Establish a quality audit mechanism, conduct internal and external audits of penetration testing work on a regular basis, check whether the test process meets the requirements of the process documents, whether the test results are accurate and reliable, whether the test records are complete and standardized, etc., and promptly discover and correct quality problems and non-conformities in the test process.
Conduct statistical analysis of test data and quality information, summarize experience and lessons, continuously optimize test processes and methods, continuously improve the penetration test quality control system, and improve the overall quality and efficiency of penetration testing of electric scooters.

8. Safety protection of penetration testing of electric scooters
During the penetration testing of electric scooters, the safety protection of testers is extremely important, and the following measures should be taken:
(I) Personal protective equipment
Testers should wear protective gloves to prevent direct contact of their hands with chemical reagents such as penetrants and removers, and avoid chemical substances from causing irritation, corrosion or poisoning to the skin of their hands.
During fluorescent penetration testing, since ultraviolet lamps are required, testers should wear protective glasses or masks to prevent ultraviolet damage to the eyes and avoid eye diseases such as photoelectric conjunctivitis.
Depending on the actual situation at the testing site, other personal protective equipment such as masks, goggles, and protective clothing can also be worn to prevent inhalation of volatile organic solvents or prevent chemical reagents from splashing onto other parts of the body.
(II) Ventilation and fire prevention
The penetration testing site should maintain good ventilation conditions, and promptly discharge harmful gases and volatile solvent vapors generated during the testing process to avoid excessive concentrations of toxic and harmful substances in the air that affect the health of testers, while reducing the risk of explosion of combustible gases.
For the inspection site using solvent-based penetrant detection agents and removers, fireworks should be strictly prohibited, and corresponding fire-fighting equipment, such as fire extinguishers and fire sand, should be equipped to deal with possible fire accidents and ensure the safety of the inspection work.
(III) Chemical management
The various chemical reagents used in penetration testing should be properly stored and managed, and stored in special chemical storage cabinets or warehouses to avoid adverse environmental conditions such as direct sunlight, high temperature, and humidity to prevent reagent deterioration, leakage, or accidents.
When using chemical reagents, they must be strictly followed in accordance with the prescribed dosage and operation methods to avoid excessive use or misoperation leading to chemical waste and environmental pollution. The chemical reagent containers after use should be properly handled and must not be discarded at will to avoid harm to the environment.

9. Comparison of electric scooter penetration testing with other non-destructive testing methods
(I) Comparison with ultrasonic testing
Inspection object: Ultrasonic testing is mainly suitable for detecting internal defects of electric scooter parts, such as internal cracks, pores, inclusions, etc., and can detect defects within a certain depth range inside the material; while penetration testing focuses on the detection of surface opening defects, and cannot effectively detect internal defects below the surface.
Detection principle: Ultrasonic testing uses the propagation characteristics of ultrasonic waves in materials. When ultrasonic waves encounter defects, reflection and refraction will occur. The existence, location and size of defects are determined by receiving and analyzing ultrasonic signals; penetrant testing is based on capillary phenomena and wetting, allowing the penetrant to penetrate into the surface open defects and display the defects through the developer.
Detection sensitivity: For surface open defects, penetrant testing has a high sensitivity and can detect cracks with a width of microns; while ultrasonic testing has a high detection sensitivity for internal defects, but for shallow and wide defects on the surface, its detection sensitivity may not be as good as penetrant testing.
Detection equipment and cost: Ultrasonic testing requires professional equipment such as ultrasonic flaw detectors, probes, coupling agents, etc. The equipment cost is relatively high, and the operation process requires certain professional knowledge and skills, and the detection cost is also high; penetrant testing equipment is simple, mainly penetrant detection agents, spray cans, ultraviolet lamps, etc., with less equipment investment and lower detection costs.
(II) Comparison with X-ray detection
Detection objects and principles: X-ray detection uses X-rays or γ-rays to penetrate materials and detects defects inside parts, such as cracks, pores, and unfused parts, based on the different degrees of attenuation of the rays in the materials. It can obtain intuitive images of the inside of the parts and is more effective for detecting internal volume defects, but has a lower sensitivity for detecting surface opening defects; penetration testing is a detection method specifically for surface opening defects.
Radiation hazards and safety: X-ray detection uses radiation sources and has radiation hazards. Strict radiation protection measures need to be taken. Detectors must undergo special radiation safety training, obtain corresponding qualification certificates, and comply with strict radiation safety operating procedures. The working environment also needs to be equipped with complete radiation protection facilities to ensure the safety of personnel and the environment; penetration testing does not have radiation hazards and uses chemical reagents. Under proper safety protection measures, the harm to personnel and the environment is relatively small, and the detection operation is relatively safe and convenient.
Testing cost and efficiency: X-ray testing equipment is expensive, such as X-ray machines or γ-ray sources, and the testing cost is high. The testing process requires a long time for X-ray exposure, film washing or digital image acquisition and processing, and the testing efficiency is relatively low; penetration testing is low in cost and fast in speed, and can complete the testing of large quantities of parts in a short time, which is suitable for rapid quality screening and quality control of electric scooter parts.
(III) Comparison with magnetic particle testing
Applicable materials: Magnetic particle testing can only be used to detect ferromagnetic materials, such as steel, etc., and cannot be used for electric scooter parts made of non-ferromagnetic materials, such as aluminum alloys and titanium alloys; penetration testing is not limited by the magnetism of the material and is suitable for surface opening defect detection of various metal and non-metal materials.
Detection sensitivity and defect types: Magnetic particle testing has a high detection sensitivity for cracks and hairlines on the surface and near the surface of ferromagnetic materials. It can detect defects with a width of micrometers and can show the approximate shape and position of the defects; Penetrant testing can detect surface opening defects of various materials, and its detection sensitivity for wider surface defects is equivalent to that of magnetic particle testing, but for tiny surface cracks, the sensitivity of fluorescent penetrant testing can reach a level similar to that of magnetic particle testing.
Detection equipment and operation: Magnetic particle testing requires the use of equipment and materials such as magnetic particle flaw detectors, magnetic particles, and magnetic suspensions. During the detection process, the workpiece needs to be magnetized and the aggregation of magnetic particles on the surface of the workpiece needs to be observed. The operation is relatively complicated and requires certain professional knowledge and skills; Penetrant testing equipment is simple, easy to operate, and easy to master. There is no need to perform special magnetization on the workpiece, and the detection process is relatively fast.

10. Future development of penetration testing of electric scooters
With the continuous development and technological progress of the electric scooter industry, penetration testing technology will also be further developed and improved in the following aspects:
(I) Performance improvement of detection agents
Develop penetration testing agents with higher sensitivity and lower toxicity to improve the detection rate of defects while reducing harm to the environment and human body. For example, develop new fluorescent dyes and coloring dyes to improve the luminous intensity and color contrast of penetrants, so that they can clearly display defects in more complex environments; improve the formula of removers and developers to improve their removal effect and imaging sensitivity, and reduce detection costs.
(II) Application of automated detection technology
Combining automated equipment and robotics technology to realize automated operation of penetration testing of electric scooter parts. Automated penetration testing systems can improve detection efficiency, reduce the impact of human factors on detection results, and improve detection quality and stability. For example, develop equipment such as automatic spraying of penetrants, automatic cleaning, and automatic imaging to achieve full automation of the detection process, which is suitable for rapid detection of electric scooter parts on large-scale production lines.
(III) Integration of image processing and analysis technology
Use advanced image processing and analysis technologies, such as digital image processing, artificial intelligence pattern recognition, etc., to automatically analyze and evaluate the defect images obtained by penetration testing. Through learning and training of a large amount of defect image data, the computer can automatically identify the type, size and severity of the defect, achieve rapid and accurate judgment of the test results, and improve the test efficiency and quality control level.
(IV) Development of multi-method joint testing
In order to more comprehensively and accurately evaluate the quality and performance of electric scooter parts, penetration testing is combined with other non-destructive testing methods such as ultrasonic testing, X-ray testing, magnetic particle testing, etc. to form a complementary testing solution. Through the comprehensive application of multiple testing methods, comprehensive detection of surface and internal defects of parts can be achieved, providing more reliable protection for the quality and safety of electric scooters.
(V) Promotion of green environmental protection testing technology
Against the background of increasingly stringent environmental protection requirements, the research and development and application of more environmentally friendly penetration testing technology will become a future development trend. For example, developing water-based penetrants to replace traditional penetrants containing organic solvents, reducing the emission of volatile organic compounds (VOCs) and reducing pollution to the environment; at the same time, optimizing the detection process, improving the utilization rate of the detection agent, reducing the generation of waste, and realizing the green development of penetration testing.
In short, as an important non-destructive testing method, penetration testing plays an irreplaceable role in the quality inspection and safety assurance of electric scooters. By deeply understanding the principles, methods, steps and applications of penetration testing in electric scooter testing, we can better utilize this technology to improve the product quality and safety of electric scooters. At the same time, constantly paying attention to the development dynamics and trends of penetration testing technology, and actively improving and perfecting the testing methods and processes will provide strong technical support for the sustained and healthy development of the electric scooter industry.