How to choose the installation position of the piezoelectric acceleration sensor

When it comes to installing an accelerometer, the goal is to ensure that the sensor can accurately capture the full range of vibration data. While ideal conditions would allow for a perfect transfer zone, the reality often depends on how the device is mounted. Keep in mind that the natural frequency of the sensor is influenced by its mass and stiffness. Any installation method that alters these properties will affect the sensor’s performance.

To achieve accurate and reliable vibration measurements, it's essential to follow key guidelines:

1. Ensure the installation doesn’t restrict the useful frequency or vibration range. 2. Avoid adding significant mass that could alter the vibration characteristics of the object being tested. 3. Establish fixed, repeatable measurement points to ensure consistency in results.

Now, let’s dive into the specific methods and considerations for properly installing an acceleration sensor.

First, the preparation of the installation surface.

For optimal performance, the surface where the sensor is mounted should be as clean and smooth as possible. This helps increase the installation resonance frequency. If available, refer to the machining specifications shown in Figure 1-1. The threaded holes used for mounting should also conform to the standards illustrated in the same figure. Any dirt or residue can be removed using solvents like acetone.

Second, the placement of the accelerometer.

In many cases, the best location for the sensor is obvious and meets the requirements for accurate vibration measurement. The primary sensitivity axis of the accelerometer should align with the direction of the vibration being measured.

Choose a position where the vibration transmission path from the sensor to the source is short and rigid. Avoid flexible connections or elements like gaskets that may introduce damping effects. For example, when measuring the vibration of rotating machinery, the bearing housing is typically the best spot for the sensor.

Vibration data is often most valuable along the axial, horizontal, and vertical axes. A three-axis acceleration sensor or a set of three single-axis sensors mounted on a three-axis base can be used to measure vibrations in all three directions at the same point. In some large-scale equipment, three individual accelerometers may be installed on the bearing ends to capture X, Y, and Z-axis vibrations effectively.