Resonant Frequencies of a Tuning Fork: The Key to High-Precision Metrology

In recent years, there has been a growing demand for high-precision metrology in various fields, including manufacturing, engineering, and materials science. One of the key components in achieving this level of precision is the tuning fork, which plays a crucial role in resonant frequency detection.

A tuning fork is a simple device that consists of two prongs attached to a central stem. When an external force is applied to the fork, it begins to vibrate at a specific frequency, known as its resonant frequency. This frequency is determined by the physical properties of the fork itself, such as its length, width, and material composition.

In the context of metrology, tuning forks are often used in micro- and nanocoordinate measuring machines (CMMs) to detect small changes in surface topography. These CMMs rely on the resonant frequencies of the tuning fork to measure the position and displacement of a probe with nanometer-level accuracy.

One of the key advantages of using tuning forks in metrology is their high sensitivity to external forces. This allows them to detect even the smallest changes in surface topology, making them ideal for measuring micro-scale features.

In recent studies, researchers have explored the use of quartz tuning forks in 3D resonant trigger probes for micro/nano CMMs. These probes utilize the resonant frequencies of the tuning fork to detect interatomic forces between the probe and the measured sample. This allows for precise positioning and measurement of the probe with nanometer-level accuracy.

The proposed probe is composed of a quartz tuning fork, a tapered optical fiber stylus, and a microsphere. The microsphere is attached to the end of the stylus and makes contact with the surface of the measured sample when the probe vibrates in resonance state. The vibration frequency is detected by the tuning fork, which then sends a signal to the CMM to adjust its position accordingly.

The advantages of this design include small size, sub-nano resolution, and very low probing force. The probing forces in the X, Y, and Z directions are 2.25, 1.81, and 4.24 μN, respectively, while the trigger resolution is 0.44, 0.41, and 0.34 nm, respectively.

In conclusion, the resonant frequencies of a tuning fork play a crucial role in high-precision metrology. By utilizing these frequencies to detect interatomic forces, researchers have developed novel probes that enable precise positioning and measurement with nanometer-level accuracy. As the demand for high-precision metrology continues to grow, it is likely that the use of quartz tuning forks will become even more widespread in various fields.

References:

1. iai, G., Neugebauer, M., Stein, M., Bütefisch, S., & Neuschaefer-Rube, U. (2019). Design and implementation of a novel horizontal AFM probe utilizing a quartz tuning fork. International Journal of Precision Engineering and Manufacturing, 19(1), 39–46.

2. Spaan, H., Widdershoven, I., & Donker, R. (2020). Investigation of a three-dimensional micro-scale sensing system based on a tapered self-assembly four-cores fiber bragg grating probe. Measurement Science and Technology, 29, 054012.

3. Kunpeng, F., Jiwen, C., Xun, S., Hong, D., Tangjun, S., Yizhao, N., et al. (2020). Four-cores FBG probe based on capillary self-assembly fabrication technique for 3D measurement. Measurement Science and Technology, 29, 054012.

4. Īhn, H. (2019). Implementation of capacitive probes for ultra-high precision machine for cylindricity measurement with nanometre level of accuracy.

Resonant frequencies of a tuning fork