Bactometer Microbial Monitoring System is the registered trademark of a series of instrumented systems using automated processes for microbiological analysis by the measurement of electrical impedance. To minimize nonmicrobial effects upon impedance measurements from physical and chemical factors, the Bactometer Microbial Monitoring System series of instruments make measurements using both a sample chamber and an uninoculated reference chamber. A single-sample chamber in any Bactometer Microbial Monitoring System is measured electrically frequently enough, relative to the rate of microbial growth, to provide a virtually continuous record of the impedance changes caused by microbial growth and activity. The Bactometer Microbial Monitoring System series of instruments have two major components — an electric measuring circuit and a data display component which is either a strip chart recorder or a computer terminal. The Bactometer Microbial Monitoring Systems have been on the market since 1976. Urine-screening and blood-culture procedures using the Bactometer 32 Microbial Monitoring System are available.