An experimental program has been carried out to investigate the efficacy of signal cross correlation techniques to provide early detection of fire. Cross-correlations were of the form <AxB> and <AxBxC>, where A, B and C were, signals from various sensors and < > denotes averages of signal products over a correlation time interval extending from present time into the past. All signals were referenced to their baseline averages extending over a time interval into the past. Tests were conducted in a room, quiescent of highly ventilated, using fire sources modeled on the test fires of European Standard EN54. Various sensors responded to airborne pyrolysis and combustion products. Discrimination of fire conditions from the exhaust of a gasoline engine and the fumes of an arc welding operation was investigated, based on NOX production or particle size, but no firm conclusions could be drawn. Further studies of the correlation are recommended.