Nari, M.I., Laksono, J.A., Hidayat, B.U. and Udin, A.R.A. 2021. The Portable Carbon Monoxide (CO) and Hydrocarbons (HC) Gas Detection System in The Car Cabin Uses The MQ-9 and TGS 2610 Sensors. Indonesian Journal of Engineering Research. 2, 1 (May 2021), 12-17. DOI:https://doi.org/10.11594/ijer.02.01.03.