Shipping by ship is still in great demand today. As the economy continues to grow, the demand for a better freight forwarder is growing to meet the number of requests for delivery of goods. Ship exhaust emissions pose a threat to the environment along with the heavy sea traffic. In this study, Nitrogen Oxide (NOx) as the main topic that deeply related to exhaust emissions is measured by NOx sensor with variation of distance to determine the effect of in measruing the concentration of NOx emissions and distribution temperature of ship exhaust gas is numerically investigated. Exhaust gas from IHC Beaver 1200 C with main engine Caterpillar 3508BDITA is simulated at wind speed 1.4m/s. The results show that farther the sensor from the tip of the exhaust stack, the smaller the measured NOx concentration. The results of numerical simulation show that the drone's safe distance from the chimney shall be more than 0.57m when measuring NOx emissions, referring to the operating temperature of 3M Polyimide Film Tape 5413.