Vehicle-mounted diesel oil quality sensor

The invention provides a vehicle-mounted diesel oil quality sensor, and relates to the technical field of diesel oil quality detection, a wide light source halogen tungsten lamp used at present is replaced by a near-infrared LED with a smaller size and a lower price, a photoelectric detector and linear filter integrated design is replaced by an MEMS spectrometer, and a metal capillary tube is upgraded. A silver mirror metal light guide capillary tube based on light path range extending and higher in sensitivity is adopted. In addition, pretreatment before diesel oil detection is realized by introducing an ultrasonic oscillation cavity. Wherein the MEMS spectrometer can change the transmission wavelength of light according to different applied voltages, so as to achieve a filtering effect. According to the LED-MEMS combined design, the light source, the lens, the silver mirror capillary tube and the MEMS spectrometer can be concentrically and coaxially installed through the optical sleeve, and the positions of