Despite the Covid-19 pandemic roaming around the planet we have been able to keep our staff safe and wheels rolling. The NL Cameras have been shipping out from our production facility to our new and existing customers around the globe.
The interest towards our technology is constantly increasing and we have extended our local reseller and distribution network. We are glad to announce our new partners:
Together with our channel partners we can provide top quality support for the NL Camera customers around the globe.
“The enthusiasm of our new channel partners around the world has been a pleasure to observe. We are currently in the process of actively expanding, especially in Europe and the APAC region. As soon as the situation allows for it, we will be in an excellent position to accelerate the on-site promotion and customer activities. We will do our best to support our partners also during the crisis, and hope everyone stays safe!“, Kai Saksela, CEO, NL Acoustics.
When comparing datasheets of different acoustic camera manufacturers, you quickly notice the number of microphones varies a lot. In this article we will explain the technology and science behind acoustic cameras and explain why having enough microphones really matters.
microphones – better acoustic sensitivity
Bigger isn’t always better, but in acoustic imaging having enough microphones plays a critical role. In general, increasing the number of microphones improves acoustical performance. Acoustic cameras generally use MEMS type microphones (microelectro–mechanical systems) as they provide great performance, stability, low power consumption, and small size. Although MEMS microphones can typically pick up loud noises (typically over 120 dB(A)), they have high self-noise level, which means that the quietest sound levels can’t be picked up with a single microphone. This self-noise however can be attenuated by combining the signal from multiple microphones. By doubling the number of microphones roughly 3 dB of noise is automatically removed. Therefore the sensitivity to detect quiet sounds can be increased by maximizing the number of microphones.
By utilizing 124 state-of-the-art microphones, the NL Camera is able to locate 0.02 l/min air leaks in optimal conditions. It is not possible to receive this type of accuracy with a smaller number of microphones, especially since the NL Camera microphones have market leading sensitivity.
In this example there are two signals from two leaks. These leaks can be missed if the sensitivity of the acoustic camera is not good enough. In the example, the 16.5 kHz leak signal can be detected with a system consisting of 32 microphones and the 18.5 kHz leak signal with a system consisting of 124 microphones.
Better detection range & resolution
Another important technical fact on the data sheets one should pay attention to is detection range, where the number of microphones plays a critical role. As sound travels through air, it is attenuated by 6 dB every time the distance is doubled. By increasing the number of microphones, the maximum detection range can also be increased: the range is roughly doubled by quadrupling the number of microphones.
One might wonder why every manufacturer doesn’t increase the number of microphones. It is easy to think that apart from increased cost there wouldn’t be any cons. This is however not true – by increasing the number of microphones the number of audio data signals that need to be processed is also increased. This requires a lot of built-in processing power. Portable acoustic cameras with a lot of microphones haven’t been widely available earlier due to lack of available internal processing power.
A quick way to reduce the required processing power would be reducing the resolution of acoustic image. An acoustic camera essentially calculates the sound level from numerous different directions (acoustic image pixels), so decreasing the number of pixels reduces the required processing power. However, an acoustic image resolution is like the resolution of your computer’s display – a small resolution makes the image blurry. In a similar way, reducing the number of sound pixels hinders the performance of the device.
By increasing the number of sound pixels, faults can be located more reliably and from longer distances. As distance increases so does the gap between the acoustic image pixels. If the number of available pixels is limited, it is difficult to determine exactly where the sound is emitted from.
While developing the NL Camera, these factors as well as portable compact size of the device have been closely considered. The NL Camera packs 124 microphones and a lot of processing power. This combination enables industry leading detection sensitivity, excellent acoustic image resolution and great range.
Entering a new decade makes a great chance to reflect on the years that have passed. Entering 2020, it feels as if it was ages since we started the company in 2015, since so much has already happened since then.
When we started the company, we had nothing but a few product prototypes that we had managed to scramble together using limited resources – together with the hunger to make a difference. We recognized a huge potential in the way sound could be utilized to bring value to people, in ways that were being completely neglected at the time. We noticed that we could do significant and meaningful things, such as reduce the energy consumption in the world, using nothing but sound. We could make an impact, while saving our customers’ money and time.
Since the beginning, we’ve continuously been focusing on the most important thing of all – the needs of our customers. Year after year, we’ve developed our solutions further, to help our customers solve their most pressing problems as well as possible. Of course, we’ve stumbled upon a lot of challenges as well; getting our solutions and advanced technologies to work in a scalable way has been no easy task.
But each year we’ve kept our focus steady, and by solving these challenges we’ve managed to build something that keeps on growing. And we know this growth will continue. Looking at our yearly turnover, our average growth rate has been 350%. The year 2019 was our most successful year so far by a huge margin. And 2020 will definitely continue this trend.
Today we are proud to have our solutions used by customers and partners in places all over the world. Next year, we will introduce a couple of new partnerships that we believe will help us spread the awareness of the great things our company can do even further.
We are proud to be changing the world using sound.