A method for particle counting based on electrical signals output from sensors in a flow cytometer instrument, wherein the electrical signals correspond to a change in impedance within a sensing zone of the flow cytometer instrument, the method comprising: Generating a normalized histogram illustrating a distribution of particles of different sizes by: selecting captured electrical signals wherein a captured electrical signal is associated with one of one or more sensors in the flow cytometer instrument, comparing parameters of each captured electrical signal with corresponding reference parameter ranges, choosing captured electrical signals whose parameters fall within corresponding reference parameter ranges, generating at least one edited histogram for each sensor using the chosen electrical signals associated with the sensor, rejecting an edited histogram associated with a sensor, if the edited histogram differs from all distinct edited histograms associated with other sensors; averaging all non-rejected edited histograms; and normalizing the averaged histogram; obtaining a corrected histogram based on a mathematical analysis of the normalized histogram and a probability that at any instant there is at least one particle in a sensing zone of the flow cytometer instrument; and calculating corrected particle counts based on the corrected histogram. Generating a normalized histogram illustrating a distribution of particles of different sizes by: selecting captured electrical signals wherein a captured electrical signal is associated with one of one or more sensors in the flow cytometer instrument, comparing parameters of each captured electrical signal with corresponding reference parameter ranges, choosing captured electrical signals whose parameters fall within corresponding reference parameter ranges, generating at least one edited histogram for each sensor using the chosen electrical signals associated with the sensor, rejecting an edited histogram associated with a sensor, if the edited histogram differs from all distinct edited histograms associated with other sensors; averaging all non-rejected edited histograms; and normalizing the averaged histogram; selecting captured electrical signals wherein a captured electrical signal is associated with one of one or more sensors in the flow cytometer instrument, comparing parameters of each captured electrical signal with corresponding reference parameter ranges, choosing captured electrical signals whose parameters fall within corresponding reference parameter ranges, generating at least one edited histogram for each sensor using the chosen electrical signals associated with the sensor, rejecting an edited histogram associated with a sensor, if the edited histogram differs from all distinct edited histograms associated with other sensors; averaging all non-rejected edited histograms; and normalizing the averaged histogram; obtaining a corrected histogram based on a mathematical analysis of the normalized histogram and a probability that at any instant there is at least one particle in a sensing zone of the flow cytometer instrument; and calculating corrected particle counts based on the corrected histogram.