Liquid-level sensor based on Michelson interferometer with double hook structure

A new type of Michelson interferometer (MI) based on a double hook structure is proposed for measurement of liquid level and temperature. The optical fiber MI based on the double-hook structure is fabricated using a hydroxide flame heating device. Furthermore, the angle and sensing length of the double-hook structure can be controlled by a rotating platform. The sensor is fixed on a ruler, which is set vertically on the iron support stand employing a beaker clamp, and the position of the beaker clamp is adjusted so that the double hook structure of the sensor overflows the water surface in the beaker. The temperature and liquid level sensitivities of the sensor are 129.8 pm/degrees C and -186.2 pm/mm, respectively. The novel optical fiber MI based on the double-hook structure has the advantages of high sensitivity, low cost and easy fabrication, which has a great market prospect in production and life.