Barometric Pressure Sensor

Atmospheric Pressure/Output voltage
125 mm Hg ( 5 in Hg) 2.5 Volts
250 mm Hg (10 in Hg) 2.0 Volts
375 mm Hg (15 in Hg) 1.5 Volts
500 mm Hg (20 in Hg) 1.0 Volts
625 mm Hg (25 in Hg) 0.5 Volts