The performances of six chlorine monitoring methods/devices have been compared to expedite the development of several novel personal monitoring devices. The devices evaluated included a diffusional colorimetric dosimeter badge from Moleculon Research Corporation, three diffusional electrochemical sensors (the Dow membrane sensor, the Dow glass frit sensor, and the Compur MonitoxTrademark of Compur Electronic Gmbh, Munich, West Germany sensor), the sulfamic acid bubbler/ion specific electrode method, and the InterScan voltammetric instrument. To be useful for personal monitoring, the electrochemical sensors must be coupled with a digital readout or microprocessor-based unit to display, store, or average chlorine concentrations detected by the sensor. A Dow built microprocessor unit and the Compur Mini-Dosimeter were evaluated. The major evaluation parameters included: applicable concentration range, linear range, accuracy, precision, effects of humidity, temperature and air velocity, and interferences from Br2, N02, SO2, H2S, and HC1. While all of the methods are useful for chlorine monitoring, each device has certain advantages and limitations. The successful utilization of these devices for determing time-weighted-average and excursion concentrations requires calibration of sensors with a reliable dynamic calibration unit, determination of field conditions encountered during sampling, and an understanding of the advantages and limitations of these devices with respect to the field conditions.