Mass flow controller with enhanced operating range

• Main Authors: SMIRNOV ALEXEI V, ZOLOCK MICHAEL J
• Format: Patent
• Language: English
• Published: 06.08.2013
• Subjects: ACTUATING-FLOATS; BLASTING; COCKS; CONTROLLING; DEVICES FOR VENTING OR AERATING; ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVEFUNCTIONING OF MACHINES OR INSTALLATIONS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; HEATING; LIGHTING; MECHANICAL ENGINEERING; PHYSICS; REGULATING; SYSTEMS FOR CONTROLLING OR REGULATING NON-ELECTRIC VARIABLES; TAPS; TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION; TECHNICAL SUBJECTS COVERED BY FORMER USPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS; THERMAL INSULATION IN GENERAL; VALVES; WEAPONS

A mass flow controller among other embodiments and method is described. The mass flow controller including a thermal mass flow sensor including at least two sensing elements coupled to a sensor tube of the mass flow controller, the thermal mass flow sensor being designed to provide a first signal indicative of flow of a gas within a first flow-rate-range and a second signal indicative of flow of the gas within a second flow-rate-range; and a control portion figured to control a valve position of the mass flow controller responsive to the first signal when the flow of the gas is within the first flow-rate-range and control the valve position of the mass flow controller responsive to the second signal when the flow of the gas is within a second flow-rate-range.