Overview

Where possible, a text output of the data collected by the instrumentation is provided. With these formats being easy to import into spreadsheet applications or to use the data with a programming language, such as Python. This allows the data to be analysed in other software, for example the redrawing of graphs or for subsequent data manipulation to be carried out.

The data is stored in a simple text file, which can be opened in an application such as Notepad. There may be one or more header rows in the file describing the organisation of the data in the file, and there may be some metadata present. More information on the common ways this data is presented are given in the formats section on this page.

Data examples

Spectroscopy

Data recorded by an IR or UV-vis spectrometer would typically consist of wavelength (or frequency) and a measured intensity of signal (transmittance or absorbance).

UV-vis kinetics

Data typically consists of time and intensity (absorbance), and may include other data such as a temperature for the measurement.

GC chromatogram

Data typically consists of time and voltage (or current) being read by the detector.

Common formats

Comma separated values (CSV)

CSV is probably the most widespread text format used for data. The file is structured with rows of data, with related values on a row (eg time and absorbance or wavelength and intensity) being separated with a comma. CSV files require any numerical values to use a dot (.) as the decimal separator. Below is a screenshot of the start of a CSV file for an IR spectrum. The first number in each row is the wavenumber with the second the transmittance (between 1 and 0).

Tab separated values (TSV)

These files separate the data using a tab rather than a comma. A few instruments still use this format, but it has mostly been displaced with CSV instead.

Fixed width

An example of fixed width data with the data displayed in columns which are separated with spaces to keep all the data aligned. This data is quite human readable, however, this format can be somewhat awkward to work with programatically, although many programming libraries do exist to aid reading these files.

eXtensible Markup Language (XML)

Extensible Markup Language (XML) uses a tag and value based method for listing data. Each tag comes as a pair with an open and close tag. open tags use the format <tag>with close tags using </tag> Below is an example of XML being used to record GPS data in a GPX file. Each trkpt tag contains the latitude and longitude for the measurement, and within this tag are secondary tags for the time of the datapoint and the elevation. Usually within the file, there is a link to a schema which describes how the file is formatted.