Skip to main content
SpringerLink
Log in

A diffraction transducer for vibration analysis

Small oscillatory displacements can be measured by the single-slit diffraction technique. The method is sensitive, accurate and adds little or no mass to the object

  • Applications
  • Published:
Experimental Mechanics Aims and scope Submit manuscript

Abstract

The recently described ditfractographic technique1, utilizing the diffraction of light passing through an aperture formed by two edges, one fixed as a reference, is used to determine small vibratory displacements. The transducer has little or no inertia, is noncontacting, and has high sensitivity and accuracy. A “time averaged” method is presented whereby peak amplitudes can be obtained with no readout instrumentation and no upper-frequency limit. Alternatively, a photodetector can be used to determine vibration amplitudes with frequency response limited only by the detector circuit.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Log in via an institution

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Institutional subscriptions

Similar content being viewed by others

Abbreviations

I :

intensity of light at a point

I o :

intensity of light at the central maximum

n :

minima or fringe order

Δn :

peak to peak change in minima or fringe order

R :

distance from the aperture to the plane of observation

w :

aperture width

Δw :

change in aperture width

Δw p-p :

peak to peak change in aperture width

x :

distance from the pattern axis of symmetry to a given minimum

λ:

wavelength of light

θ:

angle subtended at the aperture by the central maximum and a given minimum

References

  1. Pryor, T. R. andNorth, W. P. T., “The Diffractographic Strain Gage,”Experimental Mechanics,11 (12),565–568 (1971).

    Article  Google Scholar 

  2. Powell, R. L. andStetson, K. A., “Interferometric Vibration Analysis by Wavefront Reconstruction,”J. Opt. Soc. Am.,55,1593–1598 (1964).

    Google Scholar 

  3. Goldberg, J. L., “New Method for the Accurate Standardization of Mechanical Oscillations of Small Amplitude,”Jour. Acoustic Soc. America,36 (10),1922–1925 (1964).

    Google Scholar 

  4. Jenkins, F. A. andWhite, H. E., Fundamentals of Optics, McGraw-Hill Inc., New York, Third Edition, 288–292 (1957).

    Google Scholar 

Download references

Author information

Authors and Affiliations

  1. Department of Mechanical Engineering, University of Windsor, Windsor, Ontario, Can.

    W. J. Pastorius, T. R. Pryor & W. P. T. North

Authors
  1. W. J. Pastorius
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. T. R. Pryor
    View author publications

    You can also search for this author in PubMed Google Scholar

  3. W. P. T. North
    View author publications

    You can also search for this author in PubMed Google Scholar

Rights and permissions

Reprints and permissions

About this article

Cite this article

Pastorius, W.J., Pryor, T.R. & North, W.P.T. A diffraction transducer for vibration analysis. Experimental Mechanics 12, 341–344 (1972). https://doi.org/10.1007/BF02320492

Download citation

  • Issue Date:

  • DOI: https://doi.org/10.1007/BF02320492

Keywords

Search

Navigation