Abstract: The heart of this paper here is a LPG gas leakage sensor circuit that detects the outflow of LPG gas and the circuit is a gas sensor module SEN 1327. QM 6 gas sensor is used in the SEN 1327 module. The output signal from SEN 1327 gas sensor module is used to drive a 555 timer based astable multivibrator circuit. Here 555 timer works as a tone generator, the frequency of tone can be altered by varying the preset VR1. The system alerts the user via audio and visual indications.