Patent ID: 7461549
Filing Date: 2008-12-09
Classification: G01F

Abstract:
1. A mass flow verifier for verifying flow of a fluid from a mass flow device operating over an operational flow range, the mass flow verifier comprising: a system constructed and arranged so as to define different predetermined volumes so as to represent subranges within the operational flow range, each volume comprising an inlet for receiving flow from the mass flow device, and an outlet valve so that pressure changes occurring from flow from the mass flow device into a volume can be measured when the outlet valve is closed; a temperature sensor constructed and arranged so as to generate a signal representative of the temperature of the fluid within a volume when the pressure changes are being measured within the volume; a pressure sensor constructed and arranged so as to generate signals representative of the pressure changes in a volume when the pressure changes are being measured within the volume; and a controller configured and arranged so as to measure flow from the mass flow controller into any select one of the volumes as a function of the manometer pressure signal, the temperature signal, and the size of the select volume.