Abstract:The mass flow controllers currently used generally have lag in response, which leads to lag control in the mass flow controller control, which leads to the failure of the calibration of the oil gas concentration detection alarm system verification and calibration device due to the inaccurate concentration of the prepared gas. Aiming at the problem of inaccurate gas concentration caused by the slow change of the controlled gas flow rate of the verification and calibration device of the oil and gas concentration detection and alarm system, this paper designs a verification and calibration of the oil and gas concentration detection and alarm system based on a mass flow controller with a first-order and pure lag model. The device adds a control lag compensation controller to the original mass flow controller model. Its function is to free the gas control from the lag interference, so that it can quickly and stably reach the specified accuracy. We first use Simulink simulation to simulate the first-order mass flow controller with pure hysteresis model to verify its functionality and performance. The result is that the flow error is 0.89%. Finally, we used the designed mass flow controller with the first-order plus pure lag model for actual testing, and the measured flow error was 0.56%. The results show that the mass flow controller based on the first-order plus pure delay model can reduce the influence of control delay.