Up to 10% of all electrical energy used in industry goes solely into the production of compressed air. Approximately a third of this air leaks away, causing not only wasted energy and increased costs in these processes but also malfunctioning of the relevant machinery. In consequence, maintenance staff are often faced with the task of detecting compressed air escapes with very narrow-band analogue testing equipment and very rough estimated values. It is not uncommon for test measurements to have to be written down by hand.

With this in mind, SONOTEC and IMMS have now developed an innovative, digital sonographic testing device. The hand-held tester with a five-inch touchscreen provides preventive maintenance by a first-time combination. It contains an innovative measuring system that covers a wide frequency range (from 20 to 100 kHz) and innovative sensors for both structure-borne and air-borne sound, combined with smart apps that are intuitive in use. It features storage of test data, levels and spectrograms, generation of test reports and camera documentation of leaks. To transmit data efficiently and to enable the data to be integrated into existing systems, the device uses interfaces like Bluetooth, USB and SD/MMC.

IMMS was the designer of the digital components of the hardware and the developer of the FPGA firmware which is crucial to the performance of the device. IMMS also adapted and ported the Android operating system and developed algorithms by means of which the ultrasonic audio signal is converted into audible output. This last feature enables staff to make the association they have been used to on analogue devices.

SONOTEC and IMMS cooperated closely on a pilot run and the testing of the devices manufactured. The leak-finder was presented to the public for the first time at the Hannover Messe in the spring of 2016, with great success. IMMS has supported SONOTEC in the further transfer of the device to series production.