Online detection of instruments on moving equipment as a replacement for listening with the ears
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In the past, I’ve only seen sounds produced by devices that use ears to detect sound. Are there any practical and cost-effective instruments that can serve as a substitute for human hearing?
Can’t we just look at the spectrum directly?
What mechanical equipment are you referring to? Is it related to motors?
That’s indeed the case. Is there anyone who knows about this? Could you give me some information?
Motors, pumps, fans, turbines, ...
There are many similar devices. Online analysis devices typically consist of sensors installed on the equipment to measure things such as displacement, temperature, and pressure. Some of these sensors can be attached directly to the equipment. Various signals are sent through sensors, signal amplifiers, and cables to the monitoring system, where spectral analysis is carried out. These signals can also be transmitted over the network to a cloud platform, or the spectrum can be analyzed by the manufacturer of the equipment monitoring system. The vibration detection cycle of the sensor can reach a few tenths of a millisecond; after signal rejection and isolation, the system – in such cases, a scanning rate of 50 MS is already considered good. Emerging technologies have certain reference value, but the technology needs improvement; the investment costs are high, and there are expenses associated with licensing and upgrades. Now, some large pump manufacturers are also starting to offer such engineering services.
The priority is products with good cost-performance, sound quality close to that heard with the ear, and suitable for large-scale installation – for example, they can be used with power equipment of 7.5 KW or higher
Based on my experience, using eddy current amplitude detection is somewhat more feasible: a single-point detection device costs only 2,300 yuan, and it enables quantitative recording, analysis of historical trends, and early warning, helping to identify issues related to the product itself, its installation and maintenance, as well as its operation.
With such devices, digital spectral signal analysis models are generally used to achieve this. At the testing points of the devices under inspection, data collection probes (for vibration, audio, acceleration, etc.) are installed to transmit signals to the monitoring system. These signals are compared against pre-defined data models, abnormal signals are detected and analyzed, and the results are output. Some unattended pump stations and motor rooms abroad have had this system for a long time.
1 The machine cannot make decisions on its own; it still relies on humans.