FLOW CONTROL USING MASS FLOW CONTROLLER

摘要

After a product (mass flow controller) is shipped, the specifications of the mass flow controller adapted to multiple types of gas in actual use and multiple flow ranges can be altered. In the initial state of the mass flow controller, calibration gas characteristic data is collected by measuring the actual flow in response to a flow setting signal by using a calibration gas and stored in control means. Actual gas characteristic data is collected by measuring the actual flow in response to a flow setting signal by using each of multiple types of actual gas and stored in a storage medium. Before the mass flow controller is operated, the actual gas characteristic data on the actual gas to be used is read through a computer from the storage medium and the calibration gas characteristic data stored in the control means is read. With reference to the actual gas characteristic data, the calibration gas characteristic data is converted into control flow correction data. The control flow correction data is written in the control means. The actual gas flow is corrected on the basis of the control flow correction data.