User Interface

Time series plots

The central part of the main program window shows time series plots of the records in the memory buffer. The user may select which plots to show: spectrograms, fraction concentration plots, or some diagnostic parameter. The user may add any number of time series plots to window using the button Add plots or from the Time series menu.

In case of Retrospect there is only one memory buffer containing all the records that have been loaded into the program. In case of Spectops there are several memory buffers: raw records, block average records and buffers for each of the user defined averaging periods.

Clicking on the time series plots will select the current record. Details of the currently selected record are shown in a number of record view windows: size/mobility distribution, electrometer signal, diagnostic information, etc.

All the time series plots use the same horizontal time scale shown above the plots. Click the time scale and drag horizontally to pan the time, drag vertically to zoom in or out. Mouse wheel can also be used for zooming. Double click on the timescale to autofit the scale to show all the data available.

Right click on any of the time series plots allows the close the corresponding plot and also gives the option to quickly close all the plots below the current plot to quickly clean up the view.


The spectrogram plot shows the whole number density distribution as a color coded 2D image. The vertical scale of the plot is particle size or mobility and the color at each point shows the respective value of the number density distribution.

Click on the "Spectrogram" label above the plot to select which distribution to show.

Double click on the colorbar to automatically adjust the color limits. Right click and hold on the colorbar switches the color scale to a threshold mode where all point below the value are painted dark and above the value painted light.

The "fill gaps" option enables fills the gaps between the distributions – that is the time when the instrument was measuring in another operating mode.

Fraction concentration

The plot shows the total concentration in a specified fraction or the whole measured range. The plot can show either number, diameter, surface or volume concentrations.


The Electrometer current, Measurement parameter and Inversion parameter commands show the time series of one of the corresponding parameters.

Record views

Current record window shows the begin time, end time, operating mode, comment and diagnostic flags of the current record. Clicking on diagnostic flags will show the relevant plots to the time series view.

The comments field allows the user to attach comments to records. The commented records will be listed in the Comment list window for quick access.

Distribution plot shows number density or fraction plot of all the spectra that are available for the current record. The copy button copies the visible distributions to clipboard in a plain-text format.

Electrometer signals shows the table of all electrometers.

U (V)voltage of the integrating amplifiers
Iraw (fA)raw electrometer current with offset not subtracted
I (fA)processed electrometer current with the offset subtracted
Ierr (fA)noise estimate

Double click on a row adds a time series plot for the corresponding electrometer.

Electrometer signal plot shows the same data as the electrometer signal table. The blue diamond markers show the processed signal, yellow small dots show the raw signal and red errorbars show the noise level estimate.

Measurement parameters shows all the diagnostic and control parameters.

Just above the table is a filter text box which can be used to limit the list to parameters that containing the entered text fragment in their name. E.g. "flow" will only show parameters like "Sample flowspeed", "Sheath flowspeed", etc.

Just as in electrometer signals table, double clicking on a parameter will add the corresponding time series plot.

Other windows

Diagnostic status

In Spectops, the window shows all the diagnostic flags that have been active recently. The time since last occurrence is also shown. This gives the user a quick overview of warnings.

In Retrospect, the window shows all the diagnostic flags that have occurred in the currently loaded measurement data. Also shown is the number of times each flag has been seen.

Clicking on a warning will add the relevant time series plots.

Log window

Show the program log. E.g., notifications about starting, stopping measurements, connection errors. The same messages will also be written to the log files in the data folder.

Comment list

All the records that have a comment attached using the comment box in the "Current record" sub-window are shown here. Clicking on the record will make it the current selected record in the time series view as well.

The commenting feature is useful to mark records and quickly find them later.

The comments will be stored in comment files in the output folder. The comments are read by Retrospect and can also be edited/added/removed there later.

Record report

Record report shows some information about the internals of the data inversion for the currently selected record. It is generally not useful for the instrument users.