The new Environics ® Series 6123 Ozone Transfer Standard, equipped with a photometer, is the perfect system for individuals looking for a standard in ozone (O 3) monitoring and reporting programs. The S6123 system is a sister unit of the S6103 and uses O 3 to perform zero, span, precision and multi-point calibrations automatically. The S6103 system will be needed if users want to conduct span, zero, precision and multi-point calibrations using O 3; however, they can also use the system for hydrocarbons, CO, SO 2, NO, NO 2 and other target gases. The S6103 system fulfills or exceeds all U.S. Environmental Protection Agency directives for a level 3 bench or transfer standard.