Fluid sensor

The utility model discloses a fluid sensor, comprising a tube body, a floating block, a circuit board, a bottom seat, a fixing seat and a cover board. Wherein, the inside of the tube body can contain one floating block; the floating block can do the motion at the inside of the tube body; the bottom end of the tube body can combine one bottom seat; and the top end of the tube body is mutually buckled with the fixing seat; the inside of the fixing seat can be provided with the through hole of a sensing component; the inside of the fixing seat can contain one circuit board; the bottom end of the circuit board can combine an infrared sensing component; the infrared sensing component can protrude over the inside of the through hole of the sensing component; then one cover board can combine at the upper part of the fixing seat to form the fluid sensor of the utility model. In sensing the fluid, the floating block at the inside of the tube body can change the position where the floating block is at following the corresponding fluid level height. Because of the infrared sensing component emitting the infarared ray to the top face of the floating block, the infrared sensing component can receive the reflected signal from the floating block once more; the signal can be calculated through the circuit board and can be displayed on the instrument, so that the utility model can accurately sense and can measure the correct fluid data.