1results about How to "Large frequency adjustment range" patented technology

This invention discloses a dynamic calibration device for a frequency-adjustable variable cross-section gas flow meter, belonging to the field of gas flow metering technology. The device includes a variable frequency motor, a rotary valve, a fan, a rectifier, a stabilizing section, a contraction section, a development section, and a testing section connected in sequence. The rotary valve consists of a stator and a rotor; the rotor rotation causes the flow cross-sectional area to change sinusoidally, generating a standard sinusoidal flow signal. The variable frequency motor is used to adjust the rotor speed, achieving precise control of the signal frequency. The fan provides suction power. The rectifier, stabilizing, contraction, and development sections are used to ensure the airflow reaches a fully developed laminar flow state. The testing section measures the pressure gradient using a dynamic pressure sensor. This invention also provides a method for obtaining a standard volumetric flow signal by solving the analytical solution of the Navier-Stokes equations based on the pressure gradient. This device solves the problems of difficulty in controlling the generation of dynamic flow signals and the difficulty in directly tracing the source of standard flow, achieving high-precision calibration of the dynamic characteristics of the gas flow meter.