This readme file was generated on [2025-07-11] by [Jane Hodgkinson]


GENERAL INFORMATION

Title of Dataset: Data supporting the paper: Mid-IR standoff measurement of ageing-related spectroscopic changes in bitumen in the 6 µm (1700 cm−1) region. Part 1: Measurement strategy and instrument design principles, Scientific Reports 15, 25041, 2025.

Author//Principal Investigator/Supervisor Information
Name: Jane Hodgkinson
ORCID: 0000-0001-8091-7676
Institution & Theme: Cranfield University
Address: Whittle Building, Cranfield University, Cranfield, Bedfordshire, MK43 0AL, UK.
Email: j.hodgkinson@cranfield.ac.uk

Author/Associate or Co-investigator Information
Name: Nicholas Davis
ORCID: 0000-0002-4844-2532
Institution & Theme: Cranfield University
Address: Whittle Building, Cranfield University, Cranfield, Bedfordshire, MK43 0AL, UK.
Email: n.m.davis@cranfield.ac.uk

Author/Associate or Co-investigator Information
Name: Ralph P Tatam
ORCID: 0000-0001-9599-3639
Institution & Theme: Cranfield University
Address: Whittle Building, Cranfield University, Cranfield, Bedfordshire, MK43 0AL, UK.
Email: r.p.tatam@cranfield.ac.uk



Date of data collection: Data from ref [25] were collected approx 2015-2018 and replotted. Data replotted from the PNNL database have an uncertain collection date.  

Geographic location of data collection: For details see ref [25]

Information about funding sources that supported the collection of the data:
Work in this paper was supported by Highways England


SHARING/ACCESS INFORMATION

Licenses/restrictions placed on the data: CC-BY

Links to publications that cite or use the data: 
https://doi.org/10.1038/s41598-025-01135-7

Links to other publicly accessible locations of the data: 

Links/relationships to ancillary data sets: 

Was data derived from another source? Yes

If yes, list source(s): 

Ref [25]: Bowden, H. Spectroscopic Analysis of Roads at Traffc Speed. PhD Thesis, University of Reading, Reading, 2018.

PNNL database: Sharpe S.W., T.J. Johnson, R.L. Sams, P.M. Chu, G.C. Rhoderick, and P.A. Johnson. Gas-Phase Database for Quantitative Infrared Spectroscopy. Applied Spectroscopy 58, no.2, 452-1461, 2004.
DOI: 10.1366/0003702042641281

Recommended citation for this dataset: 
Data to support the publication 
Mid-IR standoff measurement of ageing-related spectroscopic changes in bitumen in the 6 µm (1700 cm−1) region. Part 1: Measurement strategy and instrument design principles, Scientific Reports 15, 25041, 2025.

DATA & FILE OVERVIEW

File List: <list all files (or folders, as appropriate for dataset organization) contained in the dataset, with a brief description>

Figure 2(a).csv
Figure 2(b).csv
Figure 4(a).csv
Figure 4(b).csv
Figure 4(c).csv

Descriptions of the data are given in the associated scientific paper

Figure. 2. (a) Diffuse reflectance spectra measurement with a hand-held FTIR spectrometer, for aged and fresh bitumen within asphalt samples25 . (b) Section of bitumen spectra overlaid on absorption spectrum for atmospheric water vapour, calculated from the PNNL database for an optical pathlength of 1m and 6.6%vol (worst-case abundance at 90% RH and 40 °C)

Figure. 4. Tuning ranges for the three lasers chosen to span the carbonyl region, overlaid onto spectra for water vapour (6%vol) and ammonia (900 ppm) for a pathlength difference of 2.2 cm. The thermal and current tuning ranges show the full range of wavelengths accessible to each laser, and range corresponding to rapid injection current modulation, respectively. Y-axis absorbance figures translate directly into uncertainty in the measurement of asphalt. 
Files (a), (b) and (c) refer to the tuning ranges of the different lasers.


Relationship between files, if important: 

Additional related data collected that was not included in the current data package: N/A

Are there multiple versions of the dataset? No
If yes, name of file(s) that was updated: 
Why was the file updated? 
When was the file updated? 

METHODOLOGICAL INFORMATION

Full methodological details (methods, data processing, instruments used, experimental conditions, materials, people involved and other details) are provided in the associated paper.

DATA-SPECIFIC INFORMATION FOR EACH FILE

Each file takes the following format:
Data columns show the x- and y- values of points plotted on the figures. Column headings correspond to the legends  and / or axis labels in the figures. SI units are used unless described / defined in the paper. All abbreviations used are defined in the paper.