Sound Cameras.

A sound camera is a measuring system that displays sound waves visually. To do this, it uses an array of microphones to precisely locate the sound sources and analyze their intensity and frequency. Depending on the model, the detected frequency range is usually between 20 Hz and 100 kHz, although specialized devices can be designed for specific industrial applications, for example ultrasound cameras with a range from 2 to 100 kHz for detecting compressed air and gas leaks, electrical partial discharges or mechanical defects such as bearing damage.

The recorded audio data is processed to form an acoustic image using special algorithms. The sound camera superimposes a colored sound map (heat map) over the real image of the scene. This allows technicians to recognize the exact position and intensity of sound sources at a glance and take targeted measures. The acoustic images and video sequences can be saved, exported and incorporated into maintenance reports. The analysis is performed directly on the camera or using mobile devices, often supported by cloud solutions for data processing.

Typical areas of application for sound cameras are production facilities, maintenance areas, electrical substations, wind turbines and piping systems.

Sound cameras (ultrasound cameras) can be used, for example, to quickly and reliably localize compressed air and gas leaks, electrical partial discharges or mechanical bearing defects in noisy industrial environments. The acoustic image is superimposed on the visual image from the digital camera in real time. The portable cameras are designed for convenient on-site use and make it easy for maintenance technicians to make leak detection part of their maintenance routine. Power losses and system defects can be minimized. Sound cameras enable precise, contact-free localization of sound sources in real time, even from greater distances and in complex system structures, without interrupting ongoing operations.

Typical applications for industrial sound cameras include the rapid localization of air, gas and vacuum leaks (leak detection) and the monitoring of partial discharges in high-voltage systems. In this way, they contribute to optimizing production processes and can help to minimize performance and energy losses as well as system defects. Sound cameras are an important tool for quality assurance and predictive maintenance. Typical locations in industrial environments are production facilities, maintenance areas, electrical substations, wind turbines and piping systems.

In addition to leak detection, sound cameras are used to analyze vibration problems, optimize sound insulation, detect bearing defects, develop quieter products or for long-term monitoring of machines.
This covers a variety of areas: 

• Machine maintenance: mechanical defects and predictive maintenance 
• Automotive: vehicle development and quality assurance 
• Building acoustics and room optimization: noise pollution, sound bridges 
• Environmental and noise protection: biological noise sources (animal populations), traffic or industrial noise 
• Aerospace: flow noise (aerodynamics) 
• Production: process-related inefficiencies due to noise (e.g. grinding or conveyor systems)

The precise localization of compressed air leaks reduces energy losses and lowers operating costs. Modern cameras can calculate the annual financial loss per leak in real time, which helps to prioritize maintenance measures. The significant reduction in troubleshooting time compared to conventional methods (e.g. soap bubble test) also saves personnel costs and minimizes production downtimes. In the longer term, regular inspections can reduce the need for additional compressors.

Decisive criteria when selecting a sound camera include: 

• Frequency range: is it suitable for the measurement application? 
• Detector range (distance to the object): how large is the system and what safety distances need to be taken into account? 
• Resolution and size of the display: visibility of details, fast localization and clear menu display 
• Storage capacity for image and video files: how many files do I want to store on the device (taking into account downstream or real-time transfer options)? 
• Interfaces for data transfer: processing of measurement data, image and video files; for integration into a network 
• Software options: data management and analysis, image processing, reporting, cloud connection, etc. 
• Size and weight: comfortable handling, even with complex or confined system structures and long work assignments 
• Temperature operating ranges: measurement stability in different plant and production areas 
• Battery life: uninterrupted operation even with prolonged use

Challenges exist at very low or very high frequencies, in highly reflective environments and when distinguishing between sound sources that are very close to one another. The correct positioning of the camera (with as clear a view of the sound source as possible) as well as the correct setting and calibration of the frequency range have an influence on the precision of the measurement results.
Modern sound cameras filter out background noise through frequency selection and directional characteristics, but very loud environments can still impair the measurement quality.

Analysis and reporting software, such as Thermal Studio from Flir, usually offers comprehensive editing tools and measurement functions for evaluating inspection data captured with a sound camera. It can also collect historical data, enabling seamless, reproducible condition monitoring of systems and machines. Anomalies can be reliably identified and presented in a professional report. The editing functions of such software can reveal important details that often remain undetected without software support.

Sound cameras (acoustic cameras) record sound waves in a wide frequency range that varies, depending on the model and application. They can detect both audible sound (low frequency, e.g. machine noise, wind noise) and ultrasound (e.g. leaks, electrical partial discharges): 

• Some devices cover frequency ranges from 125 Hz to 44 kHz, for example. They are therefore able to detect both low-frequency and ultrasonic sound sources. 
• Highly developed sound cameras, for example from Fluke or Flir, operate in ranges from 2 kHz to 100 kHz or even 130 kHz. 
• There are also systems that are specially designed for low frequencies from around 10 Hz, although the recommended working range with optimum resolution for many applications starts at around 800 Hz.