Dataset Open Access
The present dataset contains measurements of the acoustic response of screens in an impedance tube with different backings. It includes as well the characterised parameters for the screens and backings.
This dataset is released under Creative Commons with Attribution (CC BY). Any reutilisation of the present dataset in scholarly works must properly cite this work and its authors:
Statistical characterisation and responses of acoustics screens and two-layers systems M. Gaborit, L. Jaouen, O. Dazel, P. Göransson DOI: 10.5281/zenodo.3358921
Two different films (one woven and one non-woven) were sampled 40 times in order to characterise their parameters in an impedance tube. Sampling is manual, the tube inner diameter is 44.44mm and the samples are cut to a slightly large size in order to be clamped inside the tube for measurements.
The films are tested in different configurations including some with backings. Two types of backings are considered (melamine and glass wool). These backings are also characterised using 3 and 2 samples respectively. When measuring the response of the film on a backing only 20 samples of each film were used.
All measurements span the [4, 4520] Hz band. The setup is calibrated anew before each measurement session.
The films are clamped in the seam between the two parts of the tube, a 200mm air plenum is formed downstream and ends with a rigid backing. The samples for each type of film are measured within 4h.
The characterisation procedure implements the method described in the following reference:
The sample and backing piston are placed to give a rigid backing and have the sample's surface flush with the seam between the two parts of the tube. In the case of the glass wool, the material has a slight (below millimetre) embossing and the supporting surface is placed flush with respect to the seam (the top of the embossing is not considered as the sample surface).
The characterisation procedure implements the method described in the following references:
To measure responses of the film/backing systems, the backing are placed as described in the previous paragraph. The film is clamped in the seam as described in the "Films' characterisation" section. A plastic grid with thin struts is placed upstream to prevent the film from bending. This setup allows for easily changing the film without replacing the backing sample. Films' samples 1 to 20 are used for response measurements. Measurement of the grid response on a rigid backing and an air plenum of 200mm are provided for reference.
The piece of software controlling the rig implements a 3-microphones technique described in the following references:
Structure of the datasets and files
The present dataset comprises two parts. The actual traces and associated measurement parameters as exported from TubeCell are found in the directory
measurements. The results from the characterisation process as exported with RoKCell are in the
characterisations folder. These results were augmented with direct measurements of the weights and thickness of the samples (both for the films and the backings).
The measurements are stored in the
measurements directory. There are several sub-directory for each of the measurement sessions:
backings: measurements for the caracterisation of the two backings (all samples, with and without grid)
grid: measurements of the grid alone on a rigid backing and with a 200mm air plenum
nonwoven_alone: measurements for the caracterisation of the non-woven film on a 200mm air plenum, no grid (all 40 samples)
woven_alone: measurements for the caracterisation of the woven film on a 200mm air plenum, no grid (all 40 samples)
nonwoven_on_glasswool: measurements of the response of 20 non-woven film samples clamped with a grid upstream and the same glass wool sample downstream on a rigid backing
nonwoven_on_melamine: measurements of the response of 20 non-woven film samples clamped with a grid upstream and the same melamine sample downstream on a rigid backing
woven_on_glasswool: measurements of the response of 20 woven film samples clamped with a grid upstream and the same glass wool sample downstream on a rigid backing
woven_on_melamine: measurements of the response of 20 woven film samples clamped with a grid upstream and the same melamine sample downstream on a rigid backing
Each measurement is stored into a
.irk and a
.rok file. The first one contains some meta-data on the measurement process, the second contains the actual traces.
Structure of irk files
.irk files contain the following meta-data:
Structure of rok files
.rok files contain the following vector (column-major). The first line is to be omitted when reading the files, it contains the columns title. The columns are these:
characterisations contains YAML 1.2 files created from the output files of the characterisation software, exploiting the measurement data. There are three subdirectories:
backingscontains the characterisation of the backings (each sample and an average file)
nonwovencontains the characterisation of the non-woven film (each sample and an average file)
wovencontains the characterisation of the woven film (each sample and an average file)
For further inquiry write to gaborit at kth dot se