Gas Alarm System upto 6 different Gases

The objective of this system is to give audio/ visual alarm, log alarm condition with timestamp, send notification over network or web / app. The system shall have a rasberry pi, 7" screen, and pressure sensors. The system will will connected to pressure sensors which since pressure of gas. If pressure is in desired range then normal will be displayed on screen otherwise LOW pressure or HIGH pressure condition will be displayed along with Audio (Beeping)