Abstract: The present invention relates to a portable, personal breath tester device for testing the blood alcohol content of the user of the device. The breath tester includes an electronic sensor for providing an output voltage signal with an amplitude level that varies as a function of the alcohol content of the breath sample. The output voltage signal is coupled as an input signal to analog circuitry for comparing the input signal to predefined voltage thresholds associated with known blood alcohol contents. The analog circuitry generates an output signal to a display comprising a first and second LED, wherein the illumination of a specific LED corresponds to a predefined blood alcohol content range.