onlineIR

Allows .spc files exported from Mettler Toledo iC IR to be read, plotted and evaluated in Python and Jupyter notebooks

Usage

Reading the spectra

Read the folder by initializing the IR_spectra object
spec = IR_spectra(<folder>)

Checking the Spectra

IR_spectra.print_stats()
Returns the acquisition time and duration along with the time samples taken during this time. Further the spectral range and resolution is displayed.

3D Plot of the spectra

IR_spectra.print_stats()
Creates a 3D Plot of the gathered data (Intensity as a function of time and wave number). When using in a jupyter notebook, use %matplotlib widget to get an interactive view. The following optional arguments can be supplied:

• t_ref = 0 set the time in seconds to be used as a reference for the intensities
• freq_min = 0 set the minimum frequency to be included in the plot
• freq_max = inf set the maximum frequency to be included in the plot

Spectra at certain point in time

IR_spectra.plot_spectra(<time>)
Plot the spectra at a certain time <time> (given in seconds). Optional arguments:

• t_ref = 0 set the time in seconds to be used as a reference for the intensities
• freq_min = 0 set the minimum frequency to be included in the plot
• freq_max = inf set the maximum frequency to be included in the plot
• peaks = None if given a numeric value: Highlights peaks above this value and prints a list of peaks

Time dependence of a peak

IR_spectra.plot_time(<freq>)
Plots the time dependence of a given signal at <freq>. Optional arguments:

• width = 1 include wave numbers above and below the given signal (helps when peaks shift due to temperature)
• t_ref = 0 set the time in seconds to be used as a reference for the intensities
• t_min = 0 set start time in seconds
• t_max = inf set end time in seconds

Extract data for further processing

IR_spectra.get_data(<freq>) Returns the data for the given signal as a x- and y-list. Optional arguments:

• t_ref = 0 set the time in seconds to be used as a reference for the intensities
• width = 0 include wave numbers above and below the given signal (helps when peaks shift due to temperature)
• t_start = 0 set start time in seconds
• t_stop = inf set end time in seconds
• invert = False invert the signal (convert from absorbance to transmission), automatically enforces normalization
• normalize
  • normalize = 0 no normalization (default)
  • normalize = 1 simple normalization to range of 0 to 1 by min and max value
  • normalize = 2 normalization via extrapolation using predefined extrapolation function $I(t) = A_1 e^{-k_1 t} + A_2 e^{-k_2 t} + C$