Vibration and Vibration Isolation in Precision Measurement

Vibration and Vibration Isolation in Precision Measurement

Vibration and Vibration Isolation

Precision measurement relies on reliable positioning stability, but environmental and equipment vibrations can cause relative motion between the sample under test and the measurement system, resulting in measurement errors that significantly reduce the repeatability of results. Therefore, vibration isolation technology is required to reduce the impact of vibrations to an acceptable level.

1、Sources of Vibration

Vibrations during the measurement process are typically caused by both internal and external factors.

1.Internal Factors

（1）Vibrations generated by the operation of fans in the computer host accompanying the measuring instrument;

（2）Continuous vibrations generated by the built-in motion control system of the measuring instrument during operation;

（3）Vibrations generated by the operation of motors in the moving parts of the measuring instrument, etc.

2.External Factors

（1）Operation of heavy equipment such as punch presses, machine tools, and air compressors within the same workshop;

（2）Vibrations caused by people walking, hand carts, and forklifts moving;

（3）Vibrations transmitted through the foundation from nearby road traffic, subway operations, construction work, etc.

2、How to minimize the impact of vibration on measurements

Given the ubiquity of vibration, appropriate vibration isolation measures are essential.

1. Internal Measures

（1）High-rigidity, high-damping base: Provides a high-inertia, high-damping reference platform for measurement instrument, such as a marble platform. Marble has high density, a low coefficient of thermal expansion, and extremely high hardness. It is not easily affected by environmental factors and possesses excellent vibration damping and absorption properties. The entire range of WALE’s precision measurement instrument utilizes high-quality natural marble for the worktable, fully leveraging its superior physical properties to ensure the utmost stability of the instrument itself.

（2）High-rigidity frame: The instrument can adopt rigid structures such as box-type or gantry-type designs to prevent structural deformation or resonance caused by vibrations. The monolithic square steel frame used in WALE’s FD series surface contour measuring instruments exemplifies this design philosophy, significantly enhancing the instrument’s rigidity and effectively suppressing structural vibrations during the measurement process.

2.External Measures

（1）Air-float vibration isolation: This method uses compressed air to form an elastic air cushion that isolates vibrations. Shaanxi WALE’s ITC series of intelligent real-time tracking measuring instruments employs this vibration isolation technique, effectively isolating low-frequency vibrations from the ground.

（2）Elastic material vibration isolation: Taking rubber as an example, this method utilizes the material’s inherent elastic deformation to absorb and dissipate vibrations. WALE has incorporated high-performance rubber vibration damping elements at the connection points between the internal marble bases and the frames of its various instrument models to absorb the medium- and high-frequency vibrations generated by the instrument itself.

（3）Installation of independent foundations: Construct a foundation (such as a separate concrete block) for high-precision instrument that is independent of the building’s main structure, and isolate it from the surrounding ground using an isolation trench to fundamentally sever the transmission path of external vibrations.

（4） Appropriate site selection and layout: Locate the measurement room away from obvious vibration sources such as stamping presses, air compressors, roads, or railways.