Abstract: This paper expounds the characteristics of the smoke sensor having single-source and dual-ionization chambers. It can be made very small, compact, highly sensitive and efficient for smoke detection. Measured data indicate that under the condition of 9 volts,we can obtain output signals over 1.5 volts as long as the rate of eliminating light is 0.5%/m. The signals are then processed by an amplifier and a control system composed of a CMOS medium-scale integrated circuit. Thus, a highsensitive smoke detector is formed.
The smoke detector, when undergoing high and low temperature (+50~-20) tests for 96 hours under conditions of relative humidity in the 90~95% range, has not shown obvious variations in volt-ampere characteristics. The amplification and control systems are normal, with no misalarm phenomenon. The results demonstrate that the smoke sensor of single-source and dual-ionization chambers can be widely used for the prevention of fire and the detection of smoke contamination.

Key words: detector, smoke senser, ionization chambers, radiation source