Very low power consumption micromachined CO sensors

Au-doped tin oxide thin films have been deposited upon Si, micromachined structures. Anew technique to operate the device, named fast pulsed temperature supplying, is presented: The sensor heater is periodically supplied each 0.5-180 s, with a duty cycle of 100 ms. Compared to the case of a constantly applied power, the fast pulsed operating mode of the sensor device allows a strong reduction of power consumption: when the period is 20 s the reduction is equivalent to 200 times and consumption is 500 W. Furthermore, for periods up to 20 s,sensor response increases. (C) 1998 Elsevier Science S.A. All rights reserved.