The invention provides an
ion mobility
spectrometer and a carrier gas flow control method thereof. The
ion mobility
spectrometer comprises a migration tube used for completing
ion migration, an
ionization source used for generating
reagent ions, a sample
introduction device used for conveying a sample gas into the migration tube, a
molecular sieve used for
drying and purifying a carrier gas, and a flow
control unit, a
temperature control unit, a
humidity sensing unit and a processor unit, which are used for measuring and controlling temperature,
humidity and the carrier gas flow. According to the ion mobility
spectrometer provided by the invention, a humidification
bottle and a flow valve are arranged to adjust and control the
humidity of the carrier gas in the migration tube, and humidity sensors are arranged at a gas outlet of the migration tube and an outlet end of the
molecular sieve to compare a humidity difference detected by the two and judge whether the
molecular sieve is ineffective or not; an expert assistance PID control method is used for controlling the carrier gas flow, in order to improve the control precision and stability of the carrier gas flow; and the ion mobility spectrometer provided by the invention adopts an
embedded design, thereby being convenient to use, strong in flexibility and suitable for onsite application.