Worksheet 4.2: An absorption photometer for instruction in school (4/6)

Saving spectra

Spectra are saved by one click on the symbol shown on the right. For that there are two data formats available: A proprietary format with the filename extension *.spec, and the format *.csv, which can be worked on with the spreadsheet programmes of Microsoft^® Office and OpenOffice.

With a spreadsheet programme it is possible for instance to subtract a dark current spectrum from a spectrum measured in brightness to obtain a spectrum corrected for the dark current signal, and the result can be graphically depicted.

Incorporation of earlier measured spectra

Spectra saved in the *.spec format may be re-opened, shown and worked on by clicking the shown symbol.

Colour bar

Underneath the spectra a colour bar will be put from 380 to 780 nm which shows the colours seen by the human eye. This is very helpful for people that are not familiar with colours and the corresponding wavelengths.

Spectral lines

The emission lines of many elements may be shown or hidden, single or in groups in the data window. This is of great use in analysis of gas discharges, energy saving lamps, or burning matches to identfy the elements by the help of their emission lines.

Two data windows

This opens a second data window, which is useful when investigating different types of spectra at the same time, for example spectra of the intensity.

Several spectra

It is hereby possible to freeze a recently measured spectrum as a graphics in the data window while the measurement is constantly in progress and graphically shown. Every click on the symbol freezes another spectrum. This facilitates the visual observation of dynamic changes. Saving the entire set of spectra in *.spec or *.csv format is not possible.