Justin Sheard, Fluke Industrial Imaging Expert
In the world of automotive manufacturing, precision engineering, automation, and rigorous quality control processes are not just best practices—they are necessities. As vehicles become increasingly complex, with electric drivetrains, advanced safety features, and high-performance expectations, manufacturers must ensure that every component meets strict standards for reliability and performance. One critical aspect of this quality assurance process is verifying leak tightness and structural integrity in components such as windows and doors, EV battery compartments, and truck axle enclosures.
Fluke SB140 Sound Beacon with the Fluke ii905 Acoustic Imager used in a vehicle tightness test visually displaying a leak.
Leak testing, historically a labor-intensive and sometimes subjective process, has evolved significantly with the introduction of acoustic imaging and ultrasound-based inspection methods. This article explores the advantages of ultrasound leak detection, specifically utilizing the Fluke SB140 Sound Beacon in conjunction with the Fluke ii905 or ii915 Acoustic Imager, to address modern automotive manufacturing challenges. We will also examine how this method compares to traditional leak detection approaches, and why it offers a compelling solution for increasing accuracy and efficiency across multiple vehicle components.
Testing Goals and Component Integrity in Automotive Manufacturing
Windows and Doors
Ensuring the tightness of vehicle windows and doors is paramount to maintaining cabin comfort, minimizing wind noise, and preventing water ingress. Manufacturers perform leak detection to identify failures in seals, welds, and gaskets that could lead to warranty claims or dissatisfied customers. These tests are generally performed at the end of the assembly line or in quality control labs.
Traditionally, these components are tested using water spray booths, vacuum methods, or pressure decay systems. However, these tests can be slow and not always effective at pinpointing the exact leak location. Ultrasound detection, particularly when used with tools like the Fluke SB140 Sound Beacon and acoustic imagers, allows inspectors to visualize leak paths directly and rapidly.
EV Battery Compartments
Electric vehicle (EV) battery compartments present a unique set of challenges. These enclosures must be hermetically sealed to meet ingress protection (IP) standards, typically IP67 or higher, to prevent water or dust contamination. A leak in the battery enclosure can lead to severe safety risks, including short circuits or thermal events.
While helium leak testing and immersion tests are widely used in the industry for battery enclosures, these methods require pressurization, specialized equipment, and can be time-consuming. Acoustic imaging with a sound beacon provides a non-invasive alternative that can identify seal failures without pressurization, making it ideal for sensitive or complex assemblies.
Truck Axle Compartments
Truck axle and differential compartments must retain lubricants and remain free of contaminants. Leaks in these systems can result in mechanical failures, increased wear, and costly downtime. The structural complexity of these components, with several potential failure modes, require a time-consuming manual leak detection process before lubricants are added. Some testing methods are pressurized air with soap bubbles, pressurized tracer gas with sniffer, or hydrostatic testing.
By using the SB140 Sound Beacon within the sealed axle compartment, maintenance and quality personnel can efficiently locate leak points by scanning with a Fluke acoustic imager and noting where the sound is exiting.
The Role of Ultrasound Leak Detection in Automotive Manufacturing
The Fluke SB140 Sound Beacon emits a constant sound signal in the ultrasonic range at about 40 kHz. When placed inside a sealed compartment, the ultrasound fills the space and seeks the path of least resistance, escaping through leak points.
Using the Fluke ii905 or ii915 Acoustic Imager in "Beacon Mode," operators can scan the exterior surface of a component and visually detect where ultrasound is escaping. The imager displays visual representation of the leak onscreen and is overlayed on top of a visual image of the compartment. The beacon mode filters and removes all noise other than a small band centered on 40 kHz. This removes the concern of background noise adversely affecting the inspection. Operators can clearly see where ultrasound is escaping and thus pinpoint where the leak is located.
This visual feedback dramatically reduces the time required to diagnose a leak and eliminates the guesswork associated with traditional testing methods. Moreover, because the method does not require pressure differentials, it is particularly effective for fragile, non-pressurizable, or sensitive systems.
Comparing Leak Detection Methods
The table below outlines a comparison between ultrasound acoustic imaging using the SB140 Sound Beacon and traditional leak detection methods:
| Testing Method | Pressurization Required | Leak Localization | Test Time | Sensitivity | Test Complexity |
|---|---|---|---|---|---|
| Water Spray Booth | No | Indirect | Long | Low | Very High |
| Pressure Decay | Yes | No | Long | Medium | Medium |
| Helium Leak Testing | Yes | Indirect | Long | Medium | Very High |
| Soap Bubble Testing | Yes | Manual/Visual | Long | Low | Low |
| Acoustic Imaging (SB140) | No | Direct/Visual w/ Onscreen Image | Short | High | Low |
Standards and Compliance Considerations
Automotive manufacturers must meet a range of international standards depending on the component being tested. For instance:
- IP67/IP68: Required for EV battery enclosures to ensure water and dust ingress resistance.
- IATF 16949: Governs quality management systems within the automotive sector.
- IEC 60529: Defines degrees of protection (IP codes) for enclosures.
By implementing ultrasound testing with acoustic imagers, manufacturers can not only meet these standards but also streamline compliance verification processes. The non-destructive nature of acoustic testing means no stress is applied to components, preserving their integrity during inspection.
Use Case: Streamlining End-of-Line Testing in EV Assembly
Consider a mid-sized electric vehicle manufacturer that struggled with high failure rates in post-assembly water leak testing of battery enclosures. Using a pressurized air decay method, the process required specialized chambers and extensive cycle times.
After integrating the Fluke SB140 Sound Beacon and Fluke ii905 Acoustic Imager, the manufacturer was able to reduce testing time by over 60 percent. Operators placed the beacon inside the battery enclosure before sealing, then scanned the surface for leaks, completing a full inspection within minutes. Defects were pinpointed immediately and repaired before final assembly, reducing scrap rates and eliminating unnecessary rework.
This shift in process not only improved overall quality metrics but also allowed more flexible allocation of skilled labor to other critical production tasks.
Conclusion
In an era where automotive quality demands are at an all-time high, ultrasound-based leak detection using tools like the Fluke SB140 Sound Beacon and acoustic imagers represents a transformative advancement in inspection technology. From vehicle cabins to EV battery packs and drivetrain components, this method enables faster, more precise testing with minimal setup and operator training.
By replacing or augmenting traditional methods with acoustic imaging, automotive manufacturers can achieve higher throughput, lower costs, and improved product quality—all without sacrificing compliance or safety. For companies looking to optimize their leak detection strategy, ultrasound technology is no longer a future innovation—it’s a present-day solution worth considering.
About the Author
Justin Sheard is an accomplished product development leader specializing in thermal and acoustic imaging technology, particularly in preventive maintenance applications. With multiple patents and published works, Justin is a thought leader in the industry. He is dedicated to shaping the future of preventive maintenance through innovative imaging solutions that help maintenance professionals prevent unplanned downtime and improve operational efficiency. Connect with Justin on LinkedIn.