Broadband sensors: Pinpointing leaks in compressed air systems

Leak detection on industrial supply systems for compressed air and industrial gases for the purpose of energy saving and plant safety is by far the most common application of ultrasonic technology. This is because compressed air is one of the most expensive energy sources and is responsible for 10% of industrial energy costs. It is estimated that around 30% of this expensive energy is lost simply due to leaks in compressed air systems. This makes detecting and eliminating leaks worthwhile as part of a plant-wide energy management program.

Broadband

Sonotec says a key advantage that the broadband range technology offers is evident even when searching for a leak. Many of the earlier ultrasonic detectors use piezoceramic probes, which are resonant in a very small frequency range around 40kHz. Because leaks emit broadband ultrasound, it is possible to find them with a 40kHz detector. However, the 40kHz probes can also pick up a great deal of interfering ultrasonic signals. New broadband sensors with very sensitive ultrasonic microphones and high sampling rates enhance leak detection for the user. In challenging, loud environments, the spectrogram of the display on the Sonaphone immediately informs the user if there is an interfering ultrasound and at what frequency the interference is present. Using the touchscreen, the user can simply move the frequency that they want to hear out of the range of the interfering ultrasound signals, enabling them to accurately detect leaks in these challenging environments. 

After the leak has been detected, the broadband sensors enable the leak to be automatically analysed. To correctly evaluate the leak, the user enters the system pressure and the type of gas into the device and runs the LeakExpert analysis application. With just the touch of a button, the service engineer initiates the measurement and automatic analysis of the leak, and the loss in volume per minute is displayed immediately. Additionally, the device will rank the leak in a class from 1 to 5 (1 = small leak, minor loss [green]; 5 = large leak, very high loss [red]).

The extensive documentation support embedded in the new Sonaphone is another feature. Upon completion of the measurements, a full report including photos can be generated and exported by the user. 

With the new Sonaphone and the LeakExpert app, leaks on compressed air and vacuum systems and other industrial gas lines can be detected and automatically analysed with pinpoint accuracy. The multifunctional device with touchscreen processes the ultrasound signals directly. A report can be generated quickly and easily and used as a decision-making tool for follow-up actions and as proof of success in energy management programmes. With a single click, the documentation of the results is available for management, with comprehensive information about the precise location of the leak, energy loss, a photographic record and the priority level of the repair. By standardising the process to search for and evaluate leaks, the device contributes to significant time and cost savings in maintenance. Sonotec concludes that error-prone paper records are a thing of the past, since all data can be evaluated and updated directly in the device.