| abstract |
An improved readout apparatus and method for use with a testing system such as that shown in U.S. Pat. application Ser. No. 136,778, now Pat. No. 3,764,270 is disclosed employing a holding amplifier, null detector and a potentiometer coupled to a turns counter. The output of an alcohol breath testing detector system is held in the holding amplifier (voltage follower) and compared with the voltage from the potentiometer by the null detector. When nulled, the reading of the turns counter gives an extremely accurate reading of breath alcohol level. For evidential purposes, the null detector and turns counter may be photographed. |