Abstract
The author discusses the successful use of roadside evidential breath testing systems in various countries of the world. Two studies carried out in California are described. The results show the roadside systems to be accurate and robust. Technological advances in open air breath testers are discussed including a) an improved analytical process, b) the monitoring of environmental conditions, c) the use of menu-driven processes, d) enhancing accessories, e) quality assurance standards and f) process accuracy and precision. Features to look for in open air testing equipment are listed.