Peak Detection vs. RMS Detection

As reliability monitoring systems expand over the years, a mix of different types of data collection instruments may be installed. Confusion may arise when comparing the overall values measured by each device, since differing signal detection and signal conditioning processes may be integrated into the instruments. This is especially true when accelerometers are installed and measurements are compared using a portable data collector to verify a permanently installed monitor system. Often, the values from these two different instruments may be quite different. Two signal processing methods may be in use to derive an overall amplitude value:

• True peak detection, and
• RMS detection

Each system may display information derived from the same sensor source, but the overall values will not agree. The answer lies in the signal conditioning processes.