0
October 14, 2026

Locating Loose Connection with Acoustic Imaging 

SonaVu(R) PLUS Acoustic Imaging Case Study 

During an infrared electrical inspection of the LN14 Case Packer, a hot spot was identified around the Phase A and B connections inside its electrical cabinet. An audible buzzing noise was also coming from the cabinet. Together, these findings prompted further inspection with an acoustic imaging camera. 

Bringing Electrical Defects into Focus™

Acoustic imaging cameras use an array of microphones to detect high-frequency sound and overlay its location on a live image. For electrical inspections, this helps technicians locate discharge activity and narrow their investigation to a specific component or connection. 

Inspection procedure 

Gilles used a SonaVu Plus to scan the suspect area and locate the strongest ultrasonic signal. The acoustic image pinpointed activity at the upper terminal/contact region on Phase B, displaying a maximum level of 48 dB. 

Figure 1. The suspect upper terminal/contact region is circled in this cabinet view, identifying the area selected for closer inspection. 

The infrared image showed where abnormal heating was present, while the acoustic image helped focus the investigation on the source of the ultrasonic activity. The equipment was then safely isolated so the suspect component could be disassembled and inspected. 

Figure 2. Infrared view showing the hot spot around the Phase A and B connections.
Figure 3. Acoustic view displaying a maximum level of 48 dB at the upper terminal/contact region on Phase B.

Results 

Disassembly revealed visible heat and contact damage in the same area identified by acoustic imaging. By combining an audible warning with infrared and ultrasound measurements, the team was able to narrow the investigation and confirm damage at the suspected location. 

Figure 4. Disassembled LN14 Case Packer component, with the inspection area circled.
Figure 5. Close-up of the visible heat and contact damage found during disassembly.

This case highlights the value of using complementary inspection technologies. Each provided a different piece of evidence, helping the team move from an abnormal sound and hot spot to a focused inspection of the affected component.