US5884231A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Processor apparatus and method for a process measurement signal
Assignee: Endress and Hauser SE and Co KG
•
Filing: 1996-12-11
•
Granted: 1999-03-16
•
Expires: 2016-12-11
Abstract
Abstract A method and apparatus for processing a time domain reflectometry (TDR) signal having a plurality of reflection pulses to generate a valid output result corresponding to a process variable in a vessel. The method includes the steps of establishing an initial boundary signal before the process variable is locates in the vessel, storing the initial boundary signal, detecting the TDR signal, and determining a baseline signal by subtracting the initial boundary signal from the TDR signal. The method also includes the steps of establishing a signal pattern having a time range based on the width of reflection pulses in the baseline signal, comparing the baseline signal to the signal pattern until a reflection pulse in the baseline signal matches the signal pattern, determining a maximum value of the reflection pulse that matches the signal pattern, and calculating an output result based on the maximum value.
Inventors
- 👤 Kenneth Lee Perdue
- 👤 Richard B. Swager
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 16:29
CPC Classifications
G; G01; G01F; G01F23/00; G01F23/22; G01F23/28; G01F23/284; G01F23/296; G01F23/2962
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
135 words
A method for processing a time domain reflectometry (TDR) signal having a plurality of reflection pulses to generate a valid output result corresponding to a process variable in a vessel, the method comprising the steps of: establishing an initial boundary signal before the process variable is located in the vessel; storing the initial boundary signal; detecting the TDR signal; determining a baseline signal by subtracting the initial boundary signal from the TDR signal; establishing a signal pattern having a time range based on the width of reflection pulses in the baseline signal; comparing the baseline signal to the signal pattern until a reflection pulse in the baseline signal matches the signal pattern; determining a maximum value of the reflection pulse that matches the signal pattern; and calculating an output result based on the maximum value.
Claim 2
Independent Claim
135 words
A method for processing a time domain reflectometry (TDR) signal having a plurality of reflection pulses to generate a valid output result corresponding to a process variable in a vessel, the method comprising the steps of: establishing an initial boundary signal before the process variable is located in the vessel; storing the initial boundary signal; detecting the TDR signal; determining a baseline signal by subtracting the initial boundary signal from the TDR signal; establishing a signal pattern having a time range based on the width of reflection pulses in the baseline signal; comparing the baseline signal to the signal pattern until a reflection pulse in the baseline signal matches the signal pattern; determining a maximum value of the reflection pulse that matches the signal pattern; and calculating an output result based on the maximum value.
Claim 3
Dependent Claim
47 words
The method of claim 1 further comprising the steps of determining point on the initial boundary signal and a corresponding point on the TDR signal and calculating a correction factor by subtracting the point on the initial boundary signal from the corresponding point on the TDR signal.
Claim 4
Dependent Claim
30 words
The method of claim 2 further comprising the step of adding the correction factor to the TDR signal to establish a valid TDR signal prior to determining the baseline signal.
Claim 5
Dependent Claim
24 words
The method of claim 1 further comprising the step of establishing a threshold voltage prior to comparing the baseline signal to the signal pattern.
Claim 6
Dependent Claim
20 words
The method of claim 4 further comprising the step of inverting negative-going components of the reflection pulses to positive-going components.
Claim 7
Dependent Claim
31 words
The method claim 5 wherein the step of establishing a signal pattern includes the step of determining at least four points within the time range in proximity to the threshold voltage.
Claim 8
Dependent Claim
41 words
The method of claim 6 wherein the step of comparing the baseline signal to the signal pattern includes the step of searching for a reflection pulse where the four points in proximity to the threshold voltage occur within the time range.
Claim 9
Dependent Claim
34 words
The method of claim 3 further comprising the step of inverting the correction factor to a positive value prior to adding the correction factor to the TDR signal to establish the valid TDR signal.
Claim 10
Independent Claim
142 words
A method for processing or time domain reflectometry (TDR) signal having a plurality of reflection pulses to generate a valid output result corresponding to a process variable in a vessel, the method comprising the steps of: establishing an initial boundary signal before the process variable is located in the vessel; storing the initial boundary signal; detecting the TDR signal; determining a point on the initial boundary signal and a corresponding point on the TDR signal; calculating a correction factor by subtracting the point on the initial boundary signal from the corresponding point on the TDR signal; adding the correction factor to the TDR signal to establish a valid signal; determining a baseline signal by subtracting the initial boundary signal from the valid TDR signal; determining a maximum value of the baseline signal; and calculating an output result based on the maximum value.
Claim 11
Independent Claim
142 words
A method for processing or time domain reflectometry (TDR) signal having a plurality of reflection pulses to generate a valid output result corresponding to a process variable in a vessel, the method comprising the steps of: establishing an initial boundary signal before the process variable is located in the vessel; storing the initial boundary signal; detecting the TDR signal; determining a point on the initial boundary signal and a corresponding point on the TDR signal; calculating a correction factor by subtracting the point on the initial boundary signal from the corresponding point on the TDR signal; adding the correction factor to the TDR signal to establish a valid signal; determining a baseline signal by subtracting the initial boundary signal from the valid TDR signal; determining a maximum value of the baseline signal; and calculating an output result based on the maximum value.
Claim 12
Dependent Claim
34 words
The method of claim 9 further comprising the step of inverting the correction factor to a positive value prior to adding the correction factor to the TDR signal to establish the valid TDR signal.
Claim 13
Dependent Claim
51 words
The method of claim 9 further comprising the steps of establishing a signal pattern having a time range based on the width of the reflection pulses in the baseline signal and comparing the baseline signal to the signal pattern until a reflection pulse in the baseline signal matches the signal pattern.
Claim 14
Independent Claim
188 words
A method for processing a time domain reflectometry (TDR) signal having a plurality of reflection pulses to generate a valid output result corresponding to a process variable in a vessel, the method comprising the steps of: establishing an initial boundary signal before the process variable is located in the vessel; storing the initial boundary signal; detecting the TDR signal; determining a point on the initial boundary signal and a corresponding point on the TDR signal; calculating a correction factor by subtracting the point on the initial boundary signal from the corresponding point on the TDR signal; adding the correction factor to the TDR signal to establish a valid TDR signal; determining a baseline signal by subtracting the initial boundary signal from the valid TDR signal; establishing a signal pattern having a time range based on the width of the reflection pulses in the baseline signal; comparing the baseline signal to the signal pattern until a reflection pulse in the baseline signal matches the signal pattern; determining a maximum value of the reflection pulse thus matches the signal pattern; and calculating an output result based on the maximum value.
Claim 15
Independent Claim
188 words
A method for processing a time domain reflectometry (TDR) signal having a plurality of reflection pulses to generate a valid output result corresponding to a process variable in a vessel, the method comprising the steps of: establishing an initial boundary signal before the process variable is located in the vessel; storing the initial boundary signal; detecting the TDR signal; determining a point on the initial boundary signal and a corresponding point on the TDR signal; calculating a correction factor by subtracting the point on the initial boundary signal from the corresponding point on the TDR signal; adding the correction factor to the TDR signal to establish a valid TDR signal; determining a baseline signal by subtracting the initial boundary signal from the valid TDR signal; establishing a signal pattern having a time range based on the width of the reflection pulses in the baseline signal; comparing the baseline signal to the signal pattern until a reflection pulse in the baseline signal matches the signal pattern; determining a maximum value of the reflection pulse thus matches the signal pattern; and calculating an output result based on the maximum value.
Claim 16
Independent Claim
148 words
An apparatus for processing a time domain reflectometry (TDR) signal having a plurality of reflection pulses to generate a value output result corresponding to a process variable in a vessel, the apparatus comprising: means for establishing an initial boundary signal before the process variable is located in the vessel; means for storing the initial boundary signal; means for detecting the TDR signal; means for determining a baseline signal by subtracting the initial boundary signal from the TDR signal; means for establishing a signal pattern having a time range based on the width of reflection pulses in the baseline signal; means for comparing the baseline signal to the signal pattern until a reflection pulse in the baseline signal matches the signal pattern; means for determining a minimum value of the reflection pulse that matches the signal pattern; and means for calculating an output result based on the maximum value.
Claim 17
Independent Claim
148 words
An apparatus for processing a time domain reflectometry (TDR) signal having a plurality of reflection pulses to generate a value output result corresponding to a process variable in a vessel, the apparatus comprising: means for establishing an initial boundary signal before the process variable is located in the vessel; means for storing the initial boundary signal; means for detecting the TDR signal; means for determining a baseline signal by subtracting the initial boundary signal from the TDR signal; means for establishing a signal pattern having a time range based on the width of reflection pulses in the baseline signal; means for comparing the baseline signal to the signal pattern until a reflection pulse in the baseline signal matches the signal pattern; means for determining a minimum value of the reflection pulse that matches the signal pattern; and means for calculating an output result based on the maximum value.
Claim 18
Independent Claim
157 words
An apparatus for processing a time domain reflectometry (TDR) signal having a plurality of reflection pulses to generate a valid output result corresponding to a process variable in a vessel, the apparatus comprising: means for establishing an initial boundary signal before the process variable is located in the vessel; means for storing the initial boundary signal; means for detecting the TDR signal; means for determining a point on the initial boundary signal and a corresponding point on the TDR signal; means for calculating a correction factor by subtracting the point on the initial boundary signal from the corresponding point on the TDR signal; means for adding the correction factor to the TDR signal to establish a valid signal; means for determining a baseline signal by subtracting the initial boundary signal from the valid TDR signal; means for determining a maximum value of the baseline signal; and means for calculating an output result based on the maximum value.
Claim 19
Independent Claim
157 words
An apparatus for processing a time domain reflectometry (TDR) signal having a plurality of reflection pulses to generate a valid output result corresponding to a process variable in a vessel, the apparatus comprising: means for establishing an initial boundary signal before the process variable is located in the vessel; means for storing the initial boundary signal; means for detecting the TDR signal; means for determining a point on the initial boundary signal and a corresponding point on the TDR signal; means for calculating a correction factor by subtracting the point on the initial boundary signal from the corresponding point on the TDR signal; means for adding the correction factor to the TDR signal to establish a valid signal; means for determining a baseline signal by subtracting the initial boundary signal from the valid TDR signal; means for determining a maximum value of the baseline signal; and means for calculating an output result based on the maximum value.
References Cited (Backward Citations)
US3832900A
Cited
US3922914A
Cited
US3995212A
Cited
US4135397A
Cited
DE2744862A1
Cited
GB1599695A
Cited
US4322832A
Cited
GB2064128A
Cited
GB2079950A
Cited
DE3337690A1
Cited
EP0260113A2
Cited
US5391839A
Cited
US5457990A
Cited
US5420517A
Cited
US5323361A
Cited
DE4308373A1
Cited
US5345471A
Cited
US5361070A
Cited
US5361070B1
Cited
US5376888A
Cited
US5609059A
Cited
US5656774A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2002-03-15 | 2002-09-14 | 2003-03-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2006-03-15 | 2006-09-14 | 2007-03-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2010-03-15 | 2010-09-14 | 2011-03-16 | $7700.00 | Window Closed / Lapsed |