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 valve fully closing part; a calibrating volume calculation part that calculates a calibrating volume on the basis value of an integration of a flow rate measured value outputted from a flow rate sensor in a fluid parameter changing interval; and a calibration part that calibrates a flow rate on the basis of the calculated calibrating volume and a preset reference volume are provided.

Self-calibrating mechanism and self-calibrating method for flow rate sensor, and diagnostic mechanism and diagnostic method for fluid sensor

A disposable diaper which can be used both as a tape-fastening type and an underpants type by joining the both side portions of the front body part and back body part respectively to thereby form joined portions on both sides along with a waist opening and a pair of right and left leg openings and in this diaper, perforated lines are formed on the both side portions of the front body part so as to extend from an edge of the waist opening to edges of the leg openings and at least one pair of fastening tapes having hook members on inner surfaces thereof and straddle the perforated lines.

Underpants type disposable diaper

A wearing article 501 is provided on the inner surface of a chassis 502 thereof with a urine receiver 503. The receiver includes a receptacle 505 connected to a urine suction pump 500p provided separately of the article to collect urine received by the receiver and a moisture-absorbent structure. The moisture-absorbent structure includes a moisture-pervious sheet lying on the side of the receptacle facing the wearer's body, a moisture-impervious sheet lying on the side facing the wearer's garment and a moisture-absorbent material sandwiched between the moisture-pervious sheet and the liquid-impervious sheet.

Urine receiver and wearing article

A mass flow rate sensor uses a Reynolds number correction function to compensate for errors in a bypass ratio of the sensor for all gases, based on the fact that all bypass errors are functions of Reynolds number. The sensor includes a sensor tube and a bypass tube dividing flow, wherein a bypass ratio of the sensor equals a total flow rate through the sensor divided by a flow rate through just the sensor tube. Heater elements heat an upstream portion and a downstream portion of the sensor tube, and a circuit is connected to the heater elements for producing a voltage based upon a difference in resistance between the heater elements. The voltage is calibrated based on known flow rates of a reference gas, and the flow rate through the sensor is based upon the calibrated voltage multiplied by a multi-gas correction function and a Reynolds number correction function.

Reynolds number correction function for mass flow rate sensor

PURPOSE:To suppress a reactive product to grow up on a pipe wall by improving the corrosion resistance of a sensor pipe and a bypass pipe by forming a bypass duct and/or a sensor duct with Ni, platinum, Ni alloy, copper or copper alloy. CONSTITUTION:This mass flow controller 1 is provided with a flow-in route 2 for fluid, bypass duct 4 for letting the fluid flow from the flow-in route 2, sensor duct 5 branched from the bypass duct 4 so as to let the fluid flow just for a prescribed flow rate, flow-out route 3 and flow rate control valve 6. The contact gas planes of a holder 8, main body 11 and valve seat 12 or the like are mirror-finished, and gold seel rings are used for the connecting parts. In this case, the bypass duct 4 and/or the sensor duct 5 is formed by any one metal material of Ni, platinum, Ni alloy, copper and copper alloy. Thus, since the sensor pipe and the bypass pipe are composed of the metal material which corrosion resistance is higher than that of stainless steel, the corrosion resistance is improved even against halogen gas, and the generation of the reactive product can be suppressed.

Mass flow controller

PROBLEM TO BE SOLVED: To provide an inexpensive, compact, and high-performance flow rate sensor without having to enlarge its size even for high flow rates and provide a mass flow control apparatus using the same. SOLUTION: The flow rate sensor 8 branches a fluid at a prescribed ratio of divergence, makes it flow through a bypass channel 12 and a sensor channel 14 wound with a heating resistance line, which forms part of a bridge circuit, and captures the shift of heat generated by the flow of the fluid through the sensor channel 14 as an unbalance of the bridge circuit to determine the overall flow rate of the fluid as sensor output. The bypass channel is constituted of a plurality of fine channels 74 comprising one approximately linear side and a curve in contact with the one side. A ratio between the equivalent hydraulic diameter (d) of the fine channels 74 and the common logarithm of the length (T) of the fine channels 74 is 0.27 or less. The flow rate sensor is built in the mass flow control apparatus. COPYRIGHT: (C)2009,JPO&INPIT

Flow rate sensor and mass flow control apparatus using the same

PROBLEM TO BE SOLVED: To provide mass flow rate controller which enables high-accuracy assay by reflecting both pressure and mass flow and also allowing for variation in tank volume. SOLUTION: This is the method for assay of the mass flow rate controller which comprises a valve for assay 42 installed in utmost upstream of channel 6, mass flow rate control valve mechanism 10; tank 44 mounted on the channel 6 of upstream from the mass flow rate control valve mechanism 10; mass flow detecting means 8, pressure detecting means 46, means 18 for controlling the mass flow rate control valve mechanism 10, and mass flow rate assay control means 48. The method includes (1) streaming the fluid of a defined mass flow rate to the channel 6, (2) for maintain opening of the mass flow rate control valve mechanism 10 so as to match the mass flow of the fluid with the defined mass flow; (3) closing the valve for assay 42, (4) for measuring pressure and mass flow rate of the fluid after flow of the fluid running out from the tank 44 is stabilized; (5) calculating the rate of change in pressure and mass flow rate with respect to the reference pressure and mass flow measured by the same procedure in the initial state, and then (6) conduct assay, depending on the rate of change. COPYRIGHT: (C)2008,JPO&INPIT

Mass flow rate controller, assay method therefor, and semiconductor manufacturing equipment

PROBLEM TO BE SOLVED: To provide a mass flow control device and a real gas mass flow control method for controlling the flow of gas with high accuracy irrespective of the kind and properties of gas to be controlled. SOLUTION: The mass flow control device 1 has an inflow pipe part 2 into which real gas flows: a temperature sensor 7 detecting the temperature of real gas; a pressure sensor 8 detecting the pressure of the real gas; a flow sensor 5 detecting the mass flow of the real gas; a flow control valve 6 controlling the flow rate of the real gas; and a control circuit 9 regulating the opening of the flow control valve 6 based on the output of each sensor. The control circuit 9 has a digital arithmetic circuit 10 comparing a flow signal from the flow sensor 5 with a flow set value corrected with an environmental correction factor which is a ratio of real gas flow to the flow of calibration gas depending on pressure and temperature. COPYRIGHT: (C)2009,JPO&INPIT

Mass flow control device and real gas mass flow control method

PROBLEM TO BE SOLVED: To obtain a (calcium silicate)-silica composite formed body the shrinkage of which is suppressed or prevented from being caused even at high temperatures exceeding 1,000 deg.C. SOLUTION: This (calcium silicate)-silica composite formed body contains silica and calcium silicate consisting essentially of xonotlite and/or wollastonite.

Akihito Hayashi

Papers

Mass flow controller

Flow rate sensor and mass flow control apparatus using the same

Mass flow rate controller, assay method therefor, and semiconductor manufacturing equipment

Mass flow control device and real gas mass flow control method

(calcium silicate)-silica composite formed body