Back to results
US 2003/0115951 A1Published application
Apparatus and method for thermal isolation of thermal mass flow sensor
AssigneeMKS Instruments, Inc.
InventorsJesse Ambrosina, Isao Suzuki
Life of this patent
Estimating the term…
Abstract
A thermal mass flow controller includes a sensor assembly and mass flow controller housing. A thermal ground limits the conductive thermal path between the mass flow controller housing and the sensor assembly and, due to the limited cross-section of the thermal ground, substantially eliminates externally imposed thermal gradients within the sensor assembly.
Claims19
A thermal mass flow controller housing, comprising:
- a) a first chamber for enclosing a bypass tube, the first chamber including a wall for mounting a second chamber;
- b) a second chamber for enclosing a sensor tube, the second chamber including a wall for mounting to said wall of the first chamber, both walls including input and output apertures formed therethrough to provide access to the bypass tube for the sensor tube;
- and
- c) a thermal ground formed between the first and second chambers, the thermal ground comprising substantially the entire thermal conductive path between the first and second chambers.
1 more element
A thermal mass flow sensor for mounting to a wall which defines a portion of the bypass tube of a mass flow controller, the sensor comprising:
- a) a flow sensor tube defining an input end and an output end;
- b) a chamber for enclosing the flow sensor tube, the chamber including a wall for mounting to said wall of the mass flow controller, both walls including input and output apertures formed therethrough to provide respective access for the input and output ends of the sensor tube to the bypass tube;
- and
- c) a thermal ground formed between the chamber wall and said wall of the mass flow controller the thermal ground comprising substantially the entire thermal conductive path between the first and second chambers.
1 more element
A thermal mass flow controller comprising:
- a) a control valve assembly for controlling the rate of fluid flow through a conduit, the control valve assembly in thermally conductive communication with a thermal mass flow controller housing;
- b) a sensor assembly for sensing the rate of flow of the fluid through the conduit as a function of the difference in temperature between first and second regions of the conduit and for generating a control signal as a function of said rate of fluid flow, the sensor assembly in thermally conductive communication with said mass flow controller housing;
- and
- c) a thermal ground formed between the valve assembly and the sensor assembly, the thermal ground comprising substantially the entire thermal conductive path between the sensor assembly and the valve assembly.
1 more element
Dependencies are inferred from the claim text.