Performance assessment of ultra-low noise solid-state accelerometers for vibration-based diagnostics in thermal process equipment

The maturation of MEMS (micro-electromechanical systems) technology for acoustic and vibration sensing has been driven by mass-market applications, particularly in mobile communications and motion-controlled interfaces. Silicon-based MEMS accelerometers have historically been optimized for low-frequency and quasi-static (DC) applications, exhibiting higher noise spectral density characteristics compared to piezoelectric sensors. However, MEMS technology offers significant advantages in terms of miniaturization, system integration, cost-effectiveness, and repeatability, enabling deployment in challenging operational environments. Some applications demand compact packaging and enhanced performance characteristics. An example is condition monitoring of large plate heat exchangers, where fluid-flow-induced structural vibrations in inlet and outlet pipes provide diagnostic indicators. These applications require usable bandwidth up to 2 kHz and the the ability to resolve spectral amplitudes on the order of −120 to −110 dBg per Hz. This paper presents a comparative analysis of three contemporary devices designed for high-performance condition monitoring applications. We demonstrate a field-deployable implementation, including packaging for in situ measurements and the associated embedded signal processing pipeline for data acquisition. Experimental results characterize the performance boundaries and technical limitations of commercially available MEMS sensing technology.