Evaluation of measurement limits of transducer mountings in the ground

Authors

  • M.O. Al-Hunaidi Inst. for Res. in Constr., Nat. Res. Council of Canada, Ottawa, Ont., Canada
  • J.H. Rainer Inst. for Res. in Constr., Nat. Res. Council of Canada, Ottawa, Ont., Canada

Keywords:

acoustic transducers, seismometers, vibration measurement, measurement limits, transducer mountings, ground, ground vibration measurements, tapered stake, wood plate, frequency range, small instrumented hammer, impact force, response, two-channel frequency analyzer, stiff clay, fine loose sand, embedded box mounting, 120 Hz, 200 Hz, embedded Al box

Abstract

The distortion of ground vibration measurements by different methods for mounting transducers in the ground is investigated experimentally. The following mountings are considered: (i) tapered stake having cruciform cross-section; (ii) wood plate attached to the ground with threaded thin rods; and (iii) embedded aluminum box of density equivalent to that of soil. The frequency range over which acceptable measurements of ground vibrations can be made is determined for each of these mountings using frequency response tests. These tests are performed by lightly impacting the mounting with a small instrumented hammer. The impact force and the response of the mounting were recorded and analyzed on a two-channel frequency analyzer. Tests were performed at two sites: stiff clay and fine loose sand. Results show that the frequency limit for acceptable accuracy was about 200 Hz for the plate and stake mountings, whereas that for the embedded box mounting was about 120 Hz. The plate and stake mountings were found more convenient to use than the embedded box mounting

Downloads

Published

1990-07-01

How to Cite

1.
Al-Hunaidi M, Rainer J. Evaluation of measurement limits of transducer mountings in the ground. Canadian Acoustics [Internet]. 1990 Jul. 1 [cited 2022 Nov. 30];18(3):15-27. Available from: https://jcaa.caa-aca.ca/index.php/jcaa/article/view/622

Issue

Section

Technical Articles