10 Jun 2024

Porosity Measurement Device Design and Analysis

Abstract: Porosity measurements are necessary to fully characterize the acoustic properties of a porous material. Many methods exist to measure porosity with various limitations. This report details a system based on previous work to limit environmental effects on measurements.

13 Oct 2022

Data Acquisition Software for Impedance Tube Measurements

Abstract: Transmission impedance tube measurements are necessary to measure the asymmetric acoustic property known as Willis coupling. However, software is required to measure and store data from an impedance tube for acoustic material characterization. This report details the overall structure of custom-developed software built from low-level functions. Software libraries from the data acquisition system as well as the HDF5 file system are the basis for the code. A command line user interface guides a user through the necessary steps in data collection.

4 Apr 2022

Setup and Data Collection Process of an Acoustic Doppler Velocimeter (ADV) in a Laboratory Setting

Abstract: The purpose of this Coastal and Hydraulics Engineering Technical Note (CHETN) is to outline experimental set up and the data collection process of an Acoustic Doppler Velocimeter (ADV) in a laboratory setting. The Nortek Vectrino ADV will be referenced in this CHETN as will the Nortek Comprehensive Manual for Velocimeters (Nortek AS 2018). Note that Nortek no longer sells the Vectrino, but the Vector, which is similar to the Vectrino aside from only having one configuration, is available.

23 Feb 2022

Use of a Portable Friction Tester on Snow and Ice Pavement

Abstract: The objective of this project was to determine if portable friction testers could be used for friction measurements on compacted snow and ice surfaces. First, the effect of cold temperatures on the operation, consistency, and accuracy of commercially available portable pavement friction measuring tools was evaluated. Tests entailed a series of experiments in a controlled cold room environment. Two portable fixed slip continuous measurement devices and one deceleration spot measurement device were evaluated. The controlled temperature testing determined how ambient temperature and duration of exposure can affect results, but that with care, the devices could be operated in conditions as cold as ˗25°C. This was followed by using one of the devices on outdoor testing on snow, ice, and asphalt surfaces and compared the portable tester to the well-known SAAB vehicle runway friction tester. Results showed good agreement between the portable tester and the SAAB Friction tester, providing validation for the operational use of a portable tester on frozen surfaces.

24 Sep 2020

Fusion of Spectral Data from Multiple Handheld Analyzers (LIBS, XRF and Raman) for Chemical Analysis and Classification of Soil

 Abstract:  An 18-month multidisciplinary project was undertaken by JRPlumer & Associates, LLC and four subcontractors that had three technical objectives: (i) to upgrade current handheld technology for chemical analysis by X-ray fluorescence spectroscopy (XRFS), Raman spectroscopy (RS), and laser-induced breakdown spectroscopy (LIBS); (ii) to design a multisensor system based on these technologies for the rapid, in-situ chemical analysis of soils and other materials of military interest; and (iii) to investigate the classification/discrimination performance benefit that might be achieved through advanced signal pre-processing and data fusion with XRFS, RS, and LIBS analyses acquired for four suites of natural soils. Accomplishments of the program in the latter area are described in this report.