To complete our particle counter, we must add specialized electronic circuits. Amplifier circuits and filtering circuits amplify the signal and pull the smallest particles out of the noise that would otherwise obscure them. A patented digital processor compares the pulse amplitude to a voltage threshold. If the amplitude exceeds the voltage threshold for a known reference particle, the detected particle is converted as greater than that size. Additional digital circuits provide us with the means of displaying and printing these counts, and manipulating the data. We now have a particle counter