| 摘要 |
<p>Apparatus for and method of measuring mass flow of a gas in a gas delivery system. The apparatus is adapted to be connected to a source of a gas. The apparatus includes a fixed-volume chamber (14) in fluid connection with the gas source (12). A flow control device (20) can be used to control the flow of the gas into the chamber. A transducer assembly (31) comprises, in combination, a pressure transducer (30) in fluid connection with the chamber, and a signal modifying network (32) associated with the pressure transducer. The pressure transducer permits measurement of the pressure of the gas in the chamber and provides a first electrical signal representative of the pressure of the known volume of the gas. The signal modifying network modifies the first signal to produce an output signal which is proportional to PV/RT and thus directly represents the number of moles of the gas in the chamber. The apparatus is useful for calibrating mass flow controllers and the like.</p> |
