Method for measuring fluorine hydride in aluminum electrolytic plant in open way

The invention discloses a method for measuring fluorine hydride in an aluminum electrolytic plant in an open way. The method comprises the following steps of: arranging the optical emitting end and the optical receiving end of a laser detector above and at both sides of an electrolytic cell in the aluminum electrolytic plant respectively and detecting a laser light intensity variation signal which passes through the air above the electrolytic cell by adopting the laser detector; measuring an on-site wind speed signal by adopting a wind speed sensor arranged close to a skylight of the aluminum electrolytic plant; measuring an on-site humidity signal by adopting a humidity sensor arranged in the aluminum electrolytic plant; and acquiring the laser light intensity variation signal, the wind speed signal and the humidity signal by using a PLC (Programmable Logic Controller) and calculating the discharge amount of hydrogen fluoride in the aluminum electrolytic plant in real time according to a hydrogen fluoride di