The Model DF-300C Series is a mass flow controller with an integral indicator that operates on a 24-V power supply, as developed in response to the requests from users of the DF Series. It inherits the features of the DF-200C Series with enhanced convenience, including accuracy of ±1% S.P., response ≤1 sec (inall ranges), and the multiple-gas, multiple-range versatility, i.e., support of seven gases (including reference gas) and the ease ofchanging the flow rate range of each gas.