A mass flow controller comprises: a first flow meter constructed and arranged to measured flow rate of mass through the mass flow controller; a second flow meter constructed and arranged to measure flow rate of mass through the mass flow controller; a control valve constructed and arranged so as to control the flow rate of mass through the mass flow controller in response to a control signal generated as a function of the flow rate as measured by one of the flow meters; and a system controller constructed and arranged to generate the control signal, and to provide an indication when a difference between the flow rate of mass as measured by the first flow meter and the flow rate of mass as measured by the second flow meter exceeds a threshold.

System for and method of monitoring flow through mass flow controllers in real time

A mass flow control system can be self verified for its accuracy when controlling a flow to a process. The system comprises: a control valve for controlling the flow of fluid through the system as a function of a control signal; a controller for generating the control signal as a function of measured flow of fluid through the system and a targeted flow set point; a pressure sensor for measuring the controlling fluid pressure for use in measuring and verifying the flow rate; and a source of fluid for providing a known volume of fluid for use in verifying the system accuracy anytime between steps of the flow control process.

Method and apparatus for self verification of pressure based mass flow controllers

In a mass flow controller verifying system, there are provided a verifying gas line arranged in parallel to influent flow gas lines and joined into a post-confluent flow gas line, a reference volume calculating portion adapted to calculate a reference volume determined for a specified piping of a gas piping system, a verifying parameter calculating portion adapted to calculate a verifying parameter based on time series data of a measurement pressure measured by a pressure measurement unit during a control of a flow rate by a mass flow controller to be verified, and a comparing portion adapted to compare a reference parameter set based on the reference volume and the verifying parameter, whereby the verifying system can be introduced into an existing gas piping system used in a semiconductor manufacturing process and so forth at a low cost and is capable of verifying a mass flow controller quickly and accurately.

Mass flow controller verifying system, verifying method and verifying program

The present disclosure provides three-dimensional (3D) printing systems, apparatuses, methods and non-transitory computer readable media for the production of at least one desired 3D object. The 3D printer described herein comprises, inter alia, an opening that comprises a first side and a second side. A component of the 3D printing, such as a layer dispenser, may be conveyed from the first side of the opening to the second side of the opening (e.g., and vice versa) during the 3D printing. The opening may be closeable. A closure of the opening may seclude the component during at least a portion of the 3D printing. Additional features relating to components of the 3D printing systems are described herein.

Operation of three-dimensional printer components

The invention provides a total gas temperature sensor for measuring the temperature of gas in a gas flow. A gas temperature sensor in accordance with the invention comprises a measurement chamber having a gas inlet and a gas outlet; an outlet valve located at the gas outlet, operable to seal the gas outlet when in a closed position, and a temperature sensing element located in the measurement chamber. The sensor is simple to manufacture, is robust, provides for a low recovery correction and does not suffer from significant boundary layer problems.

Temperature sensor and method for measuring temperature

This disclosure relates to mass flow verification systems for and methods of measuring and verifying the mass flow through a mass flow delivery / measurement device such as a mass flow controller. A mass flow verification system comprises a preset volume, a temperature sensor, and a pressure sensor. The measured verified flow determined by the mass flow verification system can be adjusted to compensate for errors resulting from a dead volume within the mass flow measurement device.

Upstream volume mass flow verification systems and methods

This disclosure relates to mass flow verification systems for and methods of measuring and verifying the mass flow through a mass flow measurement device such as a mass flow controller. A mass flow verification system comprises a preset volume, a temperature sensor, and a pressure sensor. The measured verified flow determined by the mass flow verification system can be adjusted to compensate for errors resulting from a dead volume within the mass flow measurement device.

Upstream volume mass flow verification systems and methods field of the disclosure

PROBLEM TO BE SOLVED: To provide a system for verifying upstream mass flow capable of acquiring a gap volume for compensating for an error of a non-pressure non-sensing MFC.SOLUTION: A system 100 for verifying upstream mass flow comprises: an upstream capacity 110; a temperature sensor 130 for detecting temperature in the upstream capacity; a pressure sensor 120 configured to detect fluid pressure in the upstream capacity; and a controller 160 configured to receive a temperature signal from the temperature sensor and a pressure signal from the pressure sensor, determine flow rate of inspection fluid passing through an inspection MFC 90, and compensate for an error caused by a given gap capacity of the inspection MFC 90. The controller 160 calculates the given gap capacity on the basis of the flow rate of the inspection fluid passing through the inspection MFC 90, even both in a case that the inspection MFC 90 is in a pressure non-sensing state and in a case that the inspection MFC 90 is in a pressure sensing state.

Kaveh H. Zarkar

Papers

Upstream volume mass flow verification systems and methods

Upstream volume mass flow verification systems and methods field of the disclosure

System and method for verifying upstream volume mass flow