The TS4000H from General Monitors, Lake Forest, CA, is an intelligent toxic gas detector that is compatible with the HART communication protocol. The device monitors a variety of toxic gases including ammonia, carbon monoxide, chlorine, chlorine dioxide, hydrogen chloride, hydrogen sulfide, nitric oxide, nitrogen dioxide, oxygen deficiency, ozone, and sulfur dioxide. Features include event logs, status LED, indicator for remaining sensor life and an explosionproof housing. The system displays gas concentrations up to 500 ppm and fault codes, prompts when calibration is needed, and provides system status to the control room. HART configuration enables operation in hazardous location and access to set-up, calibration, and diagnostic options.