System and method for filtering output in mass flow controllers and mass flow meters
First Claim
1. A method for filtering an indicated flow in a mass flow device wherein said indicated flow is a function of actual gas flow, the method comprising:
- determining if said indicated flow is within an allowable deviation of a baseline;
if said indicated flow is within said allowable deviation of said baseline, outputting said indicated flow as a filtered indicated flow; and
if said indicated flow is not within said allowable deviation of said baseline, outputting a value within said allowable deviation of said baseline as said filtered indicated flow.
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Accused Products
Abstract
Embodiments of the present invention provide a method for filtering an indicated flow. One embodiment of the present invention can include the steps of (i) determining if the indicated flow is within an allowable deviation of a baseline, (ii) if the indicated flow is within the allowable deviation, outputting the indicated flow as the filtered indicated flow, and (iii) if the indicated flow is not within the allowable deviation, outputting a value that is within the predefined range as the filtered indicated flow. This embodiment of the present invention can also include determining if the indicated flow exceeds a buffer. If the indicated flow does not exceed the buffer, one embodiment of the present invention can continue to output the value that is within the allowable deviation.
13 Citations
17 Claims
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1. A method for filtering an indicated flow in a mass flow device wherein said indicated flow is a function of actual gas flow, the method comprising:
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determining if said indicated flow is within an allowable deviation of a baseline;
if said indicated flow is within said allowable deviation of said baseline, outputting said indicated flow as a filtered indicated flow; and
if said indicated flow is not within said allowable deviation of said baseline, outputting a value within said allowable deviation of said baseline as said filtered indicated flow. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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8. A method for filtering an indicated flow in a mass flow controller comprising:
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(A) outputting said Indicated flow as said filtered indicated flow for a delay period;
(B) when it is determined that said indicated flow reaches an approximately steady state, outputting said indicated flow as said filtered indicated flow;
(C) determining if said indicated flow has remained within an allowable deviation from a baseline;
(D) if said indicated flow has remained within said allowable deviation, continuing to output said indicated flow as said filtered indicated flow; and
(E) if said indicated flow has not remained within said allowable deviation;
(1) outputting a value from within said allowable deviation as said filtered indicated flow;
(2) determining if said indicated flow has exceeded a buffer;
(3) if said indicated flow has exceeded said buffer;
a) engaging a timer having a clock limit;
b) determining if said indicated flow has returned to within said buffer prior to said timer reaching said clock limit; and
c) if said indicated flow has not returned to being within said buffer prior to said timer reaching said clock limit, outputting said indicated flow as said filtered indicated flow; and
d) if said indicated flow has returned to being within said buffer prior to said timer reaching said clock limit;
i) outputting said indicated flow as said filtered indicated flow if said indicated flow is within said allowable deviation; and
ii) continuing to output said value from within said allowable deviation as said filtered indicated flow if said indicated flow is not within said allowable deviation but is within said buffer. - View Dependent Claims (9, 10, 11)
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12. A mass flow controller operable to:
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determine if an indicated flow is within an allowable deviation of a baseline;
if said indicated flow is within said allowable deviation, output said indicated flow as a filtered indicated flow; and
if said indicated flow is not within said allowable deviation, output a value that is within said allowable deviation as said filtered indicated flow. - View Dependent Claims (13, 14, 15, 16, 17)
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Specification