Issue link: https://resources.mouser.com/i/1529320
26 Advancements in Industrial Automation Measurement Resolution and Dynamic Range To determine the measurement resolution and dynamic range of the piezoelectric and VC MEMS sensors, the samples were tested in a noise-isolated chamber with state-of-the-art measurement equipment capable of micro-g measurement resolution. The units were installed in the same chamber and tested at the same time to eliminate any errors from outside environment interference. The measurements were conducted at four distinct bandwidth settings, and the residual noise was measured at each setting. The results are detailed in Table 1. The measurement resolution and dynamic range were calculated based on a 0.03kHz–10kHz bandwidth and are detailed in Table 2. The Table 1. Residual noise comparison at various bandwidths (Source: TE Connectivity) Model 0.03~300Hz µV-rms 0.03~1kHz µV-rms 0.03~3kHz µV-rms 0.03~10kHz µV-rms PE #1 27.2 30.8 39.5 57.6 PE #2 25.1 31.7 38.6 56.3 MEMS #1 377.6 405.2 412.7 498.2 MEMS #2 415.7 430.2 453.9 532.1 Table 2. Measurement resolution comparison (Source: TE Connectivity) Resolution Residual Noise Spectral Noise Dynamic Range Resolution Model mg-rms µV-rms µg-rms/√Hz dB bit PE #1 1.4 57.6 14.4 88 14.6 PE #2 1.4 56.3 14.1 88 14.6 MEMS #1 12.5 498.2 124.6 69 11.5 MEMS #2 13.3 532.1 133.0 68 11.4 resolution of the PE sensors is approximately nine times better than the VC MEMS sensors. This results in a significantly better dynamic range, which enables the end user to detect potential problems at a much earlier stage. Long-Term Stability with Minimum Drift The long-term stability of PE sensors is well known, with over 30 years of field installations. Piezoelectric crystals are inherently stable and have shown excellent stability over time. PZT crystals are the most common crystals used in PE accelerometers and are increasingly becoming the choice of crystal for most applications. VC MEMS suppliers are offering surface- micromachined VC MEMS sensors; these are much less expensive, but the end user will sacrifice measurement resolution and long-term stability.