The Edgetech Instruments Model DewTrakII MO dewpoint/humidity transmitter is an optical chill mirror hygrometer designed to continuously measure the moisture content and Barometric pressure in the motor octane testing process. It is used to monitor and ensure compliance with test standards ASTM D2700, D2699, D2885. It guarantees measurement compliance for allowable Humidity range between 25–50 gr/lb & Pressure 21–30 in Hg (0.1 in Hg). The DewTrak MO powered by 24Vdc and can be easily fitted to existing Knock engine systems. It is specifically designed to measure conditions required for Motor Octane (MON),& Research Octane (RON) It uses the chilled mirror dewpoint temperature condensation principle to determine the water vapor concentration and barometric pressure measurement of the motor intake air fuel mix. Outputs include 4 to 20mA, 0 to 5 Vdc, or 0-10Vdc and an RS232 serial port as well as electrically isolated relay contacts.