Yes, ultrasound is used for leak detection. No, we don't call it a leak detector. The CTRL ultrasound detectors detect ultrasound produced by turbulence of the molecules, which is the result of escaping gas or liquid. The "leak" can be compressed air, nitrogen, or any other type of gas. The "leak" can be a vacuum leak. The "leak" can be a valve or steam leak. However, if the leak is laminar flow (by definition = no turbulence), then the ultrasound detector will not detect the leak.
The CTRL ultrasound detectors have been proven to detect all turbulent flow leaks (not laminar). The intensity of the ultrasound is dependent upon a number of factors including sensitivity settings, distance from the source, size and shape of the hole, etc. In rare cases, large leaks can produce less ultrasound than small leaks. The detector is used to indicate and locate the leak.
The UL101 ultrasound detector does not require calibration. Ultrasound (40 kHz +/- 1.5 kHz) is detected and converted into the audible range by the UL101. The sensor, itself, does not perform any type of measurement. The converted ultrasound is output to a headset for listening or to software for trending and analysis. The software includes RMS measurement of the recorded sound, as well as other algorithms for indicating the condition of the component under test.
Using an ultrasound device with a digital meter is not particularly helpful for airborne applications such as leak and electrical detection because you cannot equate the sound to the size of the leak. Using an ultrasound device in contact with a motor bearing or gearbox that has an analog meter can be helpful to determine when the bearing shows early signs of wear and tear, even when there is no baseline for comparison. The needle will not be steady as it bounces up and down rapidly in representation of the pitting and spalling, scratches, etc. of the bearing under test. When the analog data is acquired from the ultrasound detector and converted to digital data during the data acquisition process, a digital meter may be very helpful to monitor trends over time to determine if the bearing is properly, under, or even over lubricated. However, the trend of a digital number such as RMS or decibel is not the only potential indication of a problem. Early signs of wear may have a relatively low amplitude but the erratic characteristics of the sound will be present indicating further analysis is necessary. Software with artificial intelligence or simply a good technician with a good ear are helpful to maximize the full capabilities of ultrasound for condition based maintenance.
The UL101 ultrasound detector has been written in to maintenance manuals by the military and various private organizations such as Lockheed Martin for the F-35. Much of the effort and expense required to change the manuals, train technicians, create new national stock numbers (NSNs), and more is prohibitive for our customers. Therefore, any improvements to the UL101 technology have been strictly internal so that the form and fit of the detector remains the same. Any modifications required to improve upon our technology to meet our customer needs can be discussed with our ultrasound experts. We have integrated the technology to a variety of forms and mounts.
If you have no predictive technology at your facility, experts will often suggest that ultrasound be the first due to its versatility, costs, and ease of use. If you already have a vibration program, ultrasound can easily be implemented to ensure proper lubrication...even before vibration detects problems. Use all of your predictive technologies together to get a complete and early understanding of the condition of your assets to prevent production downtime.