Considering an Acoustic Imaging Camera? Read My Buying Tips First

Each year our condition monitoring world experiences innovation at some level, be it great or small. Even through a pandemic, leading tech companies continue to transform their solutions for the greater good of reliability. A recent example is the arrival of Acoustic Imaging Camera technology, also known as ultrasonic imagers.

Acoustic imaging cameras combine extremely sensitive multi-frequency sound sensors with digital imaging technology to provide ultrasound inspectors with a clear picture – or video – that illustrates precisely where an ultrasound source originates. By marrying our vision sense with our hearing sense, a more complete outcome is possible for certain airborne ultrasound inspections.


Now, mapping the origin of a sound to its source through imagery is an innovative breakthrough, but for someone who has followed the ultrasound market for more than thirty years, I am not surprised by these developments. Let us not forget history. Ultrasound has been with us for a long time. The notion that sounds existed outside the limited range of human hearing was first discovered in the late 1800s. Some 130 years on, Pierre Currie’s research with piezoelectrics remains as relevant today as it was when the first SONAR techniques provided ship captains with a solution for navigating deadly icebergs. Today, ultrasound offers improvements to our lives through medical, industrial, navigational, and cleaning applications.

Acoustic imaging technology is not particularly new. Sound mapping techniques have existed for a few years now, focused primarily on quality control applications. More recently, some clever manufacturers pushed forward with ways to utilize the technology for condition monitoring applications, primarily for energy waste reduction and electrical asset reliability.

Buyer Personas

When new technology first hits the market, predictable buying patterns emerge. Manufacturers love the early adopters; leading-edge consumers who are always first to own the latest and greatest gadgets the market has to offer. These mavens serve as a proving ground for new tech and often, their input helps steer the development for 2nd and 3rd product generations. Early adopters exist in sharp contrast to the “wait and see” crowd.

The wait-and-see crowd prefers to remain conservatively on the sidelines. They want assurance the technology will live up to its hype before opening their own wallets. If it proves to be a passing trend, they do not want to risk their money – and ego – buying something that might end up sitting on the shelf. If the technology does take hold they will still be waiting in line when the next release is ready, preferring that the early adopters do the testing for them. Eventually, when they do come aboard, their patience is rewarded by a product with most of the early problems ironed out.

9 buying tips

For both the “early adopters” and “wait and see” users, buying tips from a trusted source helps relieve the stress associated with selecting their first ultrasound camera. After all, the investment is considerable and there may only be one chance to get it right. As someone who has lived his entire career inside the wonderful world of ultrasound, I am happy to share my insights about what you should look for in an acoustic imaging camera. This article identifies which features you should consider as “must-haves” and which ones are fluffy bits of window dressing, only there to distract buyers from less obvious deficiencies.


Buying Tip #1 – Do not buy a brand for the brand’s sake alone. 

buying tip 1

Innovations often come from the most unlikely origins, and when they do, they are honest and authentic; like the two Steve’s from Palo Alto who, in 1976, set out with a single goal to make computers personal and accessible to everyone. Had their mission been “to create the world’s first two trillion-dollar company” or “the world’s most iconic brand” they would not have succeeded beyond the confines of their parent’s garage.

Many of the ultrasonic imagers emerging today share similar humble beginnings. Born and nurtured by underfunded, tech-savvy start-ups, they eventually find their way to market by hitching themselves to well-established brands. Be mindful of this when shopping for your camera. The biggest brands may make the louder noise when it comes to trumpeting their marketing message; make sure the solutions they offer are equally capable of detecting the quietest noises in the loudest surroundings. At the end of the day, those are the ones you need to hear.

Buying Tip #2 – Take a peek behind the curtains.

buying tip 2

When manufacturers develop new products, they know they must compete for the attention of the early adopters first. Some will dress up a product with features and functions that make it stand out but do not necessarily add top priority value. This approach can confuse buyers into choosing their camera based on fluffy features rather than performance. To avoid being duped, continually ask yourself why you want an ultrasonic imager in the first place. For my money, the emphasis should be placed on sensitivity and detectability. An acoustic imaging camera should be capable of detecting multiple types of defects in varying conditions. Do not allow yourself to be distracted by less relevant window-dressing features.

Buying Tip #3 – Buy an all-purpose camera.

buying tip 3

Some acoustic imaging brands promote one camera model for finding compressed air leaks, and another for electrical assets. Really? Do we need two cameras to perform the same basic job? Steady now!

Using ultrasound to detect partial discharge in electrical assets and leaks in compressed air/vacuum systems has existed in tandem for five decades. The jobs were always performed perfectly using filtered sensors tuned in the range of 35-40kHz. This frequency choice has proven optimal for detection performance set against the contrast of loud, noisy, industrial factories. It takes into consideration the distance between source and sensor, the directionality of signal for fast pinpointing, and performance in environments characterized by elevated levels of audible background noise.

The laws of physics remain intact. The turbulent characteristics of these defects have not suddenly changed. They are as detectable today at 40kHz, as they were in the 1970s, 1980s, 1990s, 2000s, and beyond. There are no new technological discoveries or breakthroughs that warrant using a higher frequency for electrical discharges. In fact, higher frequency signals have shorter wavelengths, attenuate faster, and travel shorter distances, hampering their detectability over long expanses.

Click here to continue reading the entire article, “9 Buying Tips for Acoustic Imaging Cameras” by Allan Rienstra with SDT Ultrasound Solutions to learn about this exciting innovative technology. 

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by Allan Rienstra - SDT Ultrasound Solutions