Systems and Methods for Reference Volume for Flow Calibration

Abstract

A reference volume for use with pressure change flow rate measurement apparatus has an internal structure comprising elements with cross section and length comparable to the cross section and length of adjacent interstitial fluid regions. The reference volume may have one or more heat conduction elements exterior to and in good thermal contact with a corrosion resistant material that defines the internal fluid holding region.

What is claimed is: 
     
         1 . A system for reference volume measurements, comprising:
 a reference volume chamber with an inlet portion and an outlet portion for a fluid through the reference volume chamber;   an interior region of the reference volume chamber having a bottom wall, a ceiling wall, a central wall and a side wall, wherein the side wall and the central wall extends from the bottom wall and not conjoined with the ceiling wall, thereby making a gap for fluid movement;   an exterior wall of the reference volume chamber enveloped by a heat conduction cover for providing a thermal conduction so that the temperature is affected by ambient effects for the fluid in the reference volume chamber; and   the central wall and the side wall capable of being secured with one or more sensors or programmable logic controllers (PLCs).   
     
     
         2 . The system for reference volume measurements, as described in  claim 1 , wherein the one or more sensors is a thermal sensor chosen from a group of Negative Temperature Coefficient (NTC) thermistor, Resistance Temperature Detector (RTD), Thermocouple or Semiconductor-based sensors. 
     
     
         3 . The system for reference volume measurements, as described in  claim 1 , wherein the one or more sensors is a pressure sensor chosen from a group absolute pressure sensor, gauge pressure sensor, vacuum pressure sensor, differential pressure sensor or sealed pressure sensor. 
     
     
         4 . The system for reference volume measurements, as described in  claim 1 , wherein the central wall has a tubular structure and connects directly to the outlet portion of the reference chamber. 
     
     
         5 . The system for reference volume measurements, as described in  claim 1 , wherein the PLCs use programming languages from group comprising of function block diagram (FBD), ladder diagram (LD), structured text (ST; similar to the Pascal programming language), instruction list (IL; similar to assembly language) and sequential function chart (SFC). 
     
     
         6 . The system for reference volume measurements, as described in  claim 1 , wherein the side wall has a finned stricture, the central wall, the bottom wall and the ceiling wall are made of corrosion resistant alloy. 
     
     
         7 . The system for reference volume measurements, as described in  claim 1 , wherein the interior side wall, the central wall, the bottom wall and the ceiling wall are treated with a corrosion resistant coating. 
     
     
         8 . The system for reference volume measurements, as described in  claim 1 , wherein the side wall, the central wall, the bottom wall and the ceiling wall are covered with a corrosion resistant wire mesh. 
     
     
         9 . The system for reference volume measurement, as described in  claim 1 , wherein the fluid is chosen from a group comprising of semiconductor industry gases such as Chlorine (Cl2) and Hexafluoroethane (C2F6), water vapor, Boron Trichloride (BCl3), Silane (SiH4), Argon and Nitrogen. 
     
     
         10 . The system for reference volume measurement as described in  claim 1 , wherein the side wall, the central wall, the bottom wall and the ceiling wall are made of material chosen from a group comprising of Chrome, Stainless steel, Cobalt, Nickel, Iron, Titanium and Molybdenum. 
     
     
         11 . The system for reference volume measurement as described in  claim 1 , wherein the heat conduction element is chosen from a group comprising of copper or aluminum. 
     
     
         12 . The system for reference volume measurement as described in  claim 1 , wherein the heat conduction cover is attached to the exterior wall of the reference volume chamber by a method chosen from a group comprising of mechanical clamping, bonding with thermally conductive adhesive, brazing, or shrink fit methodologies. 
     
     
         13 . The system for reference volume measurement as described in  claim 1 , wherein the reference chamber is fabricated as sections which are welded together in sequence, by autogenous orbital welding of circular connections or electron beam welding of rectilinear and circular shapes. 
     
     
         14 . The system for reference volume measurement as described in  claim 1 , wherein the interior side wall, the central wall, the bottom wall and the ceiling wall are covered by a wire mesh chosen from a group comprising of T-304 stainless steel, T-316 stainless steel, T-31.0 SS, T-321 SS, T-347 SS or even T-430 SS. 
     
     
         15 . The system for reference volume measurements as described in  claim 1 , wherein the system can be used an individual unit. 
     
     
         16 . The system for reference volume measurements as described in  claim 1 , wherein the system can be employed as a part of complex unit comprising of one or more reference volume chambers. 
     
     
         17 . The system for reference volume measurements as described in  claim 1 , wherein the system can be employed as a part of a pipeline structure. 
     
     
         18 . The system for reference volume measurements as described in  claim 17 , wherein the system has one or more filler heat conduction cover in addition to the heat conduction cover. 
     
     
         19 . An apparatus for measurement of pressure, comprising:
 one or more pressure sensing elements, in a fluid pathway for a fluid, entering through the inlet portion, sensed via a transducer element mounted orthogonal to the fluid pathway and exiting through the outlet portion of the overall fluid pathway.   
     
     
         20 . A system for reference volume measurements, comprising:
 a reference volume chamber with an inlet portion and an outlet portion for a fluid to pass through the reference volume chamber;   the reference volume chamber having a heat exchanger chamber;   wherein a fluid entering a horizontal direction into the reference volume chamber is capable of being diverted to a vertical direction through the heat exchanger chamber to achieve a temperature stabilization during a rate of decay operation.