US20030038644A1 - Diagnostics for piezoelectric sensor - Google Patents
Diagnostics for piezoelectric sensor Download PDFInfo
- Publication number
- US20030038644A1 US20030038644A1 US09/940,329 US94032901A US2003038644A1 US 20030038644 A1 US20030038644 A1 US 20030038644A1 US 94032901 A US94032901 A US 94032901A US 2003038644 A1 US2003038644 A1 US 2003038644A1
- Authority
- US
- United States
- Prior art keywords
- piezoelectric sensor
- signal
- sensor
- diagnostic
- circuitry
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
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Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01F—MEASURING VOLUME, VOLUME FLOW, MASS FLOW OR LIQUID LEVEL; METERING BY VOLUME
- G01F1/00—Measuring the volume flow or mass flow of fluid or fluent solid material wherein the fluid passes through a meter in a continuous flow
- G01F1/05—Measuring the volume flow or mass flow of fluid or fluent solid material wherein the fluid passes through a meter in a continuous flow by using mechanical effects
- G01F1/20—Measuring the volume flow or mass flow of fluid or fluent solid material wherein the fluid passes through a meter in a continuous flow by using mechanical effects by detection of dynamic effects of the flow
- G01F1/32—Measuring the volume flow or mass flow of fluid or fluent solid material wherein the fluid passes through a meter in a continuous flow by using mechanical effects by detection of dynamic effects of the flow using swirl flowmeters
- G01F1/325—Means for detecting quantities used as proxy variables for swirl
- G01F1/3259—Means for detecting quantities used as proxy variables for swirl for detecting fluid pressure oscillations
- G01F1/3266—Means for detecting quantities used as proxy variables for swirl for detecting fluid pressure oscillations by sensing mechanical vibrations
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01F—MEASURING VOLUME, VOLUME FLOW, MASS FLOW OR LIQUID LEVEL; METERING BY VOLUME
- G01F1/00—Measuring the volume flow or mass flow of fluid or fluent solid material wherein the fluid passes through a meter in a continuous flow
- G01F1/05—Measuring the volume flow or mass flow of fluid or fluent solid material wherein the fluid passes through a meter in a continuous flow by using mechanical effects
- G01F1/20—Measuring the volume flow or mass flow of fluid or fluent solid material wherein the fluid passes through a meter in a continuous flow by using mechanical effects by detection of dynamic effects of the flow
- G01F1/32—Measuring the volume flow or mass flow of fluid or fluent solid material wherein the fluid passes through a meter in a continuous flow by using mechanical effects by detection of dynamic effects of the flow using swirl flowmeters
- G01F1/325—Means for detecting quantities used as proxy variables for swirl
- G01F1/3287—Means for detecting quantities used as proxy variables for swirl circuits therefor
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01F—MEASURING VOLUME, VOLUME FLOW, MASS FLOW OR LIQUID LEVEL; METERING BY VOLUME
- G01F25/00—Testing or calibration of apparatus for measuring volume, volume flow or liquid level or for metering by volume
- G01F25/20—Testing or calibration of apparatus for measuring volume, volume flow or liquid level or for metering by volume of apparatus for measuring liquid level
- G01F25/24—Testing proper functioning of electronic circuits
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R19/00—Arrangements for measuring currents or voltages or for indicating presence or sign thereof
- G01R19/22—Arrangements for measuring currents or voltages or for indicating presence or sign thereof using conversion of ac into dc
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- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Fluid Mechanics (AREA)
- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Measuring Volume Flow (AREA)
Abstract
Description
- The present invention relates to piezoelectric sensors of the type which are used to sense movement or vibration. More specifically, the present invention relates to diagnostics of such piezoelectric sensors.
- Piezoelectric sensors are used to sense movement or vibrations in many applications. A piezoelectric sensor comprises a piezoelectric crystal which is typically mechanically coupled to an object which produces a mechanical movement. This causes a mechanical input to the crystal which results in an electrical signal being generated across the crystal. By measuring the electrical signal, it is possible to make determinations regarding the mechanical input which was applied to the crystal.
- One application for piezoelectric sensors is in vortex flowmeters. Vortex flowmeters are capable of measuring flow of a gas or fluid (referred to as “process fluid”) by monitoring the vibration generated by a bluff body as the fluid flows past the buff body. The piezoelectric sensor is mechanically coupled to the bluff body and generates an electrical output related to the amplitude and frequency of the vibrations in the bluff body. This electrical output can be correlated to the rate at which the gas or fluid is flowing past the bluff body. Such vortex flowmeters are used in industrial processes in which it is desirable to monitor the flow rate of a process fluid.
- Failure or degradation of the piezoelectric sensor can cause inaccuracies in measurements obtained from the sensor. If a sensor has wholly or partially failed yet remains in use, the measurements generated from that sensor will be erroneous. In order to ensure that a sensor has not failed it can be necessary to periodically test the sensor. Even in situations where it is clear that the measurements are erroneous, it is still necessary to conduct tests on the sensor and measurement electronics to determine the source of the error. Such testing typically requires that the piezoelectric sensor be taken to a laboratory or placed in some sort of test fixture. This can be time consuming. In industrial process environments in which a vortex flowmeter is located at a remote location, and testing requires temporarily shutting down the process, the testing procedure can be particularly cumbersome.
- A diagnostic device for testing a piezoelectric sensor includes an AC source configured to apply an AC signal to the piezoelectric sensor at two or more different frequencies. Measurement circuitry coupled to the piezoelectric sensor measures a response of the sensor to the applied AC signal and provides a measured output related to a sensor resistance and a sensor capacitance of the piezoelectric sensor. Diagnostic circuitry provides a diagnostic output as a function of the measured output.
- FIG. 1 shows an equivalent circuit for a piezoelectric sensor.
- FIG. 2 is a simplified schematic diagram showing test circuitry for use in testing in a piezoelectric sensor.
- FIG. 3 is a graph for voltage ratio versus frequency for the circuit of FIG. 2 in which a test capacitance is 220 pf.
- FIG. 4 is a graph of calculated capacitance versus actual capacitance for the circuit of FIG. 2 in which a test capacitance is 220 pf.
- FIG. 5 is a graph of calculated resistance versus actual resistance for the circuit of FIG. 2 in which a test capacitance is 220 pf.
- FIG. 6 is a graph for voltage ratio versus frequency for the circuit of FIG. 2 in which a test capacitance is 100 pf.
- FIG. 7 is a graph of calculated capacitance versus actual capacitance for the circuit of FIG. 2 in which a test capacitance is 100 pf.
- FIG. 8 is a graph of calculated resistance versus actual resistance for the circuit of FIG. 2 in which a test capacitance is 100 pf.
- FIG. 9 is a simplified schematic diagram showing a vortex flowmeter including a piezoelectric sensor and diagnostic circuitry in accordance with the invention.
- FIG. 1 is a simplified schematic diagram of the equivalent circuit for a
piezoelectric sensor 10. Thesensor 10 can be modeled as avoltage source E S 12 coupled to aseries capacitor C S 14 which is in parallel with aleakage resistance R L 16. The sensor provides asensor output 18. - The present invention provides diagnostic information regarding operation of
sensor 10 by measuring the capacitance CS and/or the resistance RL of the sensor. Typically, a sensor which is in good working order has a very high leakage resistance RS and a series capacitance CS which is within normal operating parameters. In one aspect, the present invention applies an AC signal tosensor 10 in order to measure the values of CS and/or RL. - FIG. 2 shows
simplified testing circuitry 30 for use in testingpiezoelectric sensor 10 in accordance with one example embodiment of the invention. In FIG. 2, thesignal source 12 portion of the equivalent circuit is not illustrated forsensor 10.Circuitry 30 includes asignal generator 32 configured to apply an AC test signal topiezoelectric sensor 10. This signal can be any signal having a time varying component generated from any appropriate source. The output resistance of thesignal generator 32 is modeled as aresistance R 0 34. Atest capacitance C t 36 is coupled in series betweensource 32 andpiezoelectric sensor 10.Source 32 andsensor 10 couple to anelectrical ground 40. A cable which is used to connect topiezoelectric sensor 10 is modeled as acable capacitance C C 42 and a cable leakage-resistance R C 44. Aresponse signal output 46 is taken acrosspiezoelectric sensor 10 and applied tomeasurement circuitry 48.Circuitry 48 can comprise isolation amplification, preprocessing, compensation, digitization or other type of circuitry. In some embodiments,measurement circuitry 48 can comprise a direct connection todiagnostic circuitry 52.Diagnostic circuitry 52 receives a measuredoutput signal 50 fromcircuitry 48 and responsively provides adiagnostic output 54 related to a condition ofsensor 10.Circuitry 52 can comprise simple threshold comparison circuitry or more complex circuitry including signal processing circuitry. - In operation,
circuitry 30 can provide diagnostic information related to the operation ofsensor 10 by applying an ACsignal using source 32 and monitoringresponse signal output 46. For example, if the signal fromsource 32 is applied at two different frequencies, the values of RL and CS can be computed. If the capacitance ofsensor 10 is too small, it will appear as an open circuit. Note that the cable capacitance CC for any cabling can obscure this measurement if the open circuit occurs between the cable and thesensor 10. However, an open circuit can be detected if it occurs between the electronics (not shown in FIG. 2) and the cabling used to connectsensor 10. The leakage resistance RL appears to be zero for a short circuit and appears as the actual sensor leakage resistance if no shorts exist. Note that the measured resistance is affected by the cabling leakage-resistance RC. - The actual values of the leakage resistance RL and the sensor capacitance CS can be determined using mathematical relationships. However, diagnostics can be performed on
sensor 10 simply by monitoring theoutput 46 without requiring the following mathematical formulas be solved. In the following equations the output resistance R0 ofsignal generator 32 is neglected. This should not provide any significant error if R0 is sufficiently small. The following graphs illustrate that any such errors are only introduced for very low leakage resistances for CS and high leakage resistance for R1 and RC. -
- where ω1 and ω2 are the frequencies of two different signals from
signal generator 32 and er1 and er2 are the ratios of the output voltage atoutput 46 to the input voltage across thesignal generator 32 at the respective two test frequencies. - FIG. 3 is a graph which shows output to input ratio (er) versus frequency for various values of CS and RL where Ct is 220 pf. FIGS. 4 and 5 are graphs which show the calculated capacitance and calculated resistance, respectively, versus actual capacitance for various values of RL where the two test frequencies are 100 and 1000 Hz. FIGS. 6, 7 and 8 are graphs similar to FIGS. 3, 4 and 5, respectively, except that a test capacitance of 100 pf is used. From these graphs it can be seen that errors in the calculated values are slightly less when a lower test capacitor value is used.
- In the graphs shown in FIGS.3-8, the signal generator output resistance RO is included (having a maximum value, of for example, 13,800 ohms). For some types of signal generators, this resistance is variable depending on the output voltage level. When the resistance is zero the above equations are exact.
- FIG. 9 is a simplified block diagram showing a
vortex flowmeter 70 of the type used in a process control or monitoring system.Vortex flowmeter 70 includespiezoelectric sensor 10 mechanically coupled to abluff body 72.Bluff body 72 is placed in a pipe orconduit 74. A flow 76 (Q) of process fluidpast bluff body 72 causes vortexes 78 to be formed adjacent thebluff body 72. This induces a vibration inbluff body 72 which is transferred topiezoelectric sensor 10.Sensor 10 responsively creates an electrical signal as discussed above. This signal is amplified bydifferential amplifier 80 which couples tosensor 10 throughswitch 82. The output from thedifferential amplifier 80 is digitized by analog todigital converter 82 and provided to amicroprocessor 84. Using known equations,microprocessor 84 can calculate the flow rate based upon the digitized signal.Microprocessor 84 communicates over a process control loop such as two-wire control loop 86 through input/output circuitry 88. In some embodiment, input/output circuitry 88 can include power supply circuitry which is used to power all of the electronics ofvortex flowmeter 70 from power received throughloop 86.Loop 86 carries information related to the calculated flow such as, for example, a current I which varies in accordance with a predetermined relationship to the measured flow or a digital signal. - In accordance with the present invention,
vortex flowmeter 70 includescircuitry 30 for testing and performing diagnostics onsensor 10. In the example of FIG. 9,measurement circuitry 48 is formed by adifferential amplifier 90 and analog todigital converter 82.Microprocessor 84 is an example implantation of diagnostic circuitry. In operation,microprocessor 84 operatesswitch 82 to obtain flowrate measurements. In order to perform diagnostics,microprocessor 84 opens switch 82 and closes switch 92.Differential amplifier 90 is then configured to sense the response signal generated bysensor 10 in response tosource 32. In some embodiments,source 32 can be an AC signal of source from other circuitry such as circuitry used in analog to digital converters, etc. The amplified signal is digitized by analog todigital converter 82 and provided tomicroprocessor 84. -
Microprocessor 84 can analyze the measured output signal from the analog todigital converter 82. For example, the amplitudes of theresponse signal 46 taken whensource 32 is at two or more different frequencies can be compared to threshold values. To provide more accurate diagnostic measurements, it can also be desirable to measure the AC signal fromsource 32. Additionally, more complex analysis can be performed to obtain more detailedinformation regarding sensor 10 and specifically information related to the values for RL and CS insensor 10. Once the diagnostics operation is complete,microprocessor 84 opens switch 92 and closes switch 82 such thatflowmeter 70 can return to normal operation. - Based upon the results of the diagnostics,
microprocessor 84 can communicate information overloop 86, or through other means, and can inform an operator thatsensor 10 is in the process of failing or has already failed. Based upon the severity of the degradation ofsensor 10, in some instances it may be desirable formicroprocessor 84 to compensate flow measurements based upon the diagnostic results. For example, if thesensor 10 fails in a predictable manner, a compensation curve can be used to compensate for errors in the sensor output or flow calculation. - Diagnostics can be initiated periodically by
microprocessor 84 based upon predetermined conditions such as during prescheduled down times or constant flow periods.Microprocessor 84 can also receive commands to perform diagnostics through input/output circuitry 88. The communication can be provided through (not shown) input/output circuitry which is used to communicate with a local device or with service personnel. - Although the present invention has been described with reference to preferred embodiments, workers skilled in the art will recognize that changes may be made in form and detail without departing from the spirit and scope of the invention. Any appropriate AC signal or technique for applying to AC signal can be used. Similarly, any appropriate technique can be used to sense and process the response signal. Diagnostics can be through any appropriate technique including threshold or frequency detection techniques or through more advanced signal processing techniques. The various circuit components can be implemented in analog or digital form, or their combination. For example, the diagnostic circuitry can be analog threshold comparison circuitry.
Claims (24)
Priority Applications (6)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US09/940,329 US6531884B1 (en) | 2001-08-27 | 2001-08-27 | Diagnostics for piezoelectric sensor |
CNB028170008A CN1280639C (en) | 2001-08-27 | 2002-08-16 | Diagnostics for piezoelectric sensor |
PCT/US2002/026266 WO2003019205A1 (en) | 2001-08-27 | 2002-08-16 | Diagnostics for piezoelectric sensor |
DE60213258T DE60213258T2 (en) | 2001-08-27 | 2002-08-16 | DIAGNOSIS FOR PIEZOELECTRIC SENSOR |
EP02757209A EP1423715B1 (en) | 2001-08-27 | 2002-08-16 | Diagnostics for piezoelectric sensor |
JP2003524019A JP4519463B2 (en) | 2001-08-27 | 2002-08-16 | Diagnosis of piezoelectric sensors |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US09/940,329 US6531884B1 (en) | 2001-08-27 | 2001-08-27 | Diagnostics for piezoelectric sensor |
Publications (2)
Publication Number | Publication Date |
---|---|
US20030038644A1 true US20030038644A1 (en) | 2003-02-27 |
US6531884B1 US6531884B1 (en) | 2003-03-11 |
Family
ID=25474640
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
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US09/940,329 Expired - Lifetime US6531884B1 (en) | 2001-08-27 | 2001-08-27 | Diagnostics for piezoelectric sensor |
Country Status (6)
Country | Link |
---|---|
US (1) | US6531884B1 (en) |
EP (1) | EP1423715B1 (en) |
JP (1) | JP4519463B2 (en) |
CN (1) | CN1280639C (en) |
DE (1) | DE60213258T2 (en) |
WO (1) | WO2003019205A1 (en) |
Cited By (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP1480023A1 (en) * | 2003-05-20 | 2004-11-24 | Endress + Hauser GmbH + Co. KG | Measurement device with apparatus for recognition of connected ultrasonic sensor |
US20100045311A1 (en) * | 2008-08-20 | 2010-02-25 | Jaycee Howard Chung | Dual Electrical Current Sourcing-piezoresistive Material Self-Sensing (DEC-PMSS) System |
CN110631646A (en) * | 2018-06-22 | 2019-12-31 | 微动公司 | Vortex flowmeter supporting flow instability detection |
EP3988950A1 (en) * | 2020-10-22 | 2022-04-27 | Yokogawa Electric Corporation | Diagnostic device, diagnostic method, and field device |
WO2022128418A1 (en) * | 2020-12-17 | 2022-06-23 | Endress+Hauser Flowtec Ag | Vortex flow meter and method for testing a vortex flow meter |
US11706990B2 (en) | 2017-05-24 | 2023-07-18 | HELLA GmbH & Co. KGaA | Method for calibrating at least one sensor |
Families Citing this family (15)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
ATE378539T1 (en) * | 2005-07-22 | 2007-11-15 | Delphi Tech Inc | METHOD AND DEVICE FOR MONITORING AND ASSESSING THE FUNCTION OF A PIEZOELECTRIC ACTUATOR |
US7236113B1 (en) * | 2006-01-26 | 2007-06-26 | Emerson Process Management | Capacitance-to-digital modulator with sensor failure-mode detection |
US8217667B2 (en) * | 2009-01-16 | 2012-07-10 | Hill-Rom Services, Inc. | Method and apparatus for piezoelectric sensor status assessment |
AT11169U3 (en) * | 2009-10-22 | 2010-12-15 | Avl List Gmbh | METHOD FOR OPERATING AN ELECTROMECHANICAL CONVERTER SYSTEM AND ELECTROMECHANICAL TRANSDUCER SYSTEM |
FR2953295B1 (en) * | 2009-12-02 | 2012-05-18 | Sagem Defense Securite | METHOD OF DETECTING FAILURE OF A FREQUENCY SENSOR AND CIRCUIT FOR CARRYING OUT SAID METHOD |
US8788233B2 (en) * | 2011-01-18 | 2014-07-22 | General Electric Company | Diagnostic system and method for a thermistor amplifier circuit |
LU92090B1 (en) | 2012-10-29 | 2014-04-30 | Iee Sarl | Piezoelectric and/or electret sensing device |
EP2915255B1 (en) * | 2012-10-31 | 2016-12-28 | Diehl AKO Stiftung & Co. KG | Piezo key sensing circuit and method for testing the piezo key sensing circuit |
RU2524743C2 (en) * | 2012-11-06 | 2014-08-10 | Закрытое акционерное общество "Вибро-прибор" | Method for calibration of piezoelectric vibration transducer on operation site without dismantlement |
RU2556743C1 (en) * | 2014-03-28 | 2015-07-20 | Российская Федерация, от имени которой выступает Государственная корпорация по атомной энергии "Росатом" | Device for remote measurement of piezo-transducer signal parameters |
EP3627574B1 (en) * | 2018-09-21 | 2021-02-17 | TE Connectivity Norge AS | Method and apparatus for detecting an open circuit state in a piezoelectric element connection |
CN112415292B (en) * | 2019-08-20 | 2022-03-18 | 北京钛方科技有限责任公司 | Piezoelectric device on-line detection device and method |
WO2021031831A1 (en) | 2019-08-20 | 2021-02-25 | 北京钛方科技有限责任公司 | Online detection device and method for piezoelectric device |
WO2021061001A1 (en) | 2019-09-25 | 2021-04-01 | Rosemount Inc. | Piezoelectric transducer condition monitoring |
DE102019129177A1 (en) * | 2019-10-29 | 2021-04-29 | Krohne Messtechnik Gmbh | Vortex flow meter and method for operating a vortex flow meter |
Family Cites Families (29)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3616693A (en) | 1969-06-16 | 1971-11-02 | Fischer & Porter Co | Swirl-type flowmeter |
US3638037A (en) | 1970-05-26 | 1972-01-25 | Eastech | Automatic tracking filter |
US3709034A (en) | 1971-02-02 | 1973-01-09 | Fischer & Porter Co | Signal conditioner for recovering dominant signals from swirl-type meters |
US3719080A (en) | 1971-06-07 | 1973-03-06 | Fischer & Porter Co | Sensor probe and shield assembly for swirl-type flowmeter |
US3872385A (en) * | 1972-06-28 | 1975-03-18 | Kabusai Denshin Denwa Kabushik | Fixture for measuring parameters of quartz crystal units |
US3864972A (en) | 1973-03-12 | 1975-02-11 | Fischer & Porter Co | Signal recovery system for vortex type flowmeter |
US4270391A (en) | 1979-08-24 | 1981-06-02 | Fischer & Porter Co. | Frequency-responsive filter for flowmeter transmission system |
AT369549B (en) * | 1981-02-10 | 1983-01-10 | List Hans | TEST DEVICE FOR DETERMINING VIBRATION PROPERTIES |
JPS5918421A (en) | 1982-07-22 | 1984-01-30 | Oval Eng Co Ltd | Automatic band following filter |
US4545258A (en) | 1983-07-05 | 1985-10-08 | Rosemount Inc. | Circuit with adjustable amplitude and rolloff frequency characteristics |
US4815324A (en) | 1986-04-24 | 1989-03-28 | Mitsubishi Denki Kabushiki Kaisha | Intake air meter for an internal combustion engine |
JPH0711533B2 (en) * | 1987-03-30 | 1995-02-08 | 本田技研工業株式会社 | Vehicle collision detection device |
US4866435A (en) | 1987-10-16 | 1989-09-12 | Rosemount Inc. | Digital transmitter with variable resolution as a function of speed |
US4893035A (en) | 1988-07-18 | 1990-01-09 | Hittite Microwave Corporation | Cascaded low pass/high pass filter phase shifter system |
US5022257A (en) | 1989-01-13 | 1991-06-11 | Lew Hyok S | Impulse sensor with amplitude calibration means |
US5309711A (en) | 1991-08-21 | 1994-05-10 | Rohr, Inc. | Cascade type thrust reverser for fan jet engines |
DE69232273T2 (en) | 1991-09-24 | 2002-08-08 | Murata Manufacturing Co | An acceleration |
JP2900658B2 (en) * | 1991-09-24 | 1999-06-02 | 株式会社村田製作所 | Acceleration sensor |
JP3148940B2 (en) * | 1992-02-25 | 2001-03-26 | 株式会社トーキン | Acceleration sensor |
US5351556A (en) | 1992-03-09 | 1994-10-04 | Lew Yon S | Compound electronic filter for vortex flowmeters |
US5435188A (en) | 1992-03-09 | 1995-07-25 | Lew; Hyok S. | Electronic filter for flowmeters with compound controls |
US5372046A (en) | 1992-09-30 | 1994-12-13 | Rosemount Inc. | Vortex flowmeter electronics |
US5587663A (en) * | 1995-01-09 | 1996-12-24 | Xtal Technologies, Ltd. | Method for measuring the inductance of each resonator of a coupled-dual resonator crystal |
JPH10123171A (en) * | 1996-10-18 | 1998-05-15 | Hokuriku Electric Ind Co Ltd | Diagnosis method and self-diagnosis device of three-axis acceleration sensor |
JPH10170545A (en) * | 1996-12-13 | 1998-06-26 | Miyota Co Ltd | Self-diagnostic function for acceleration sensor and acceleration sensor with self-diagnostic function |
US5942696A (en) | 1997-03-27 | 1999-08-24 | Rosemount Inc. | Rapid transfer function determination for a tracking filter |
DE19845185B4 (en) | 1998-10-01 | 2005-05-04 | Eads Deutschland Gmbh | Sensor with resonant structure and device and method for self-test of such a sensor |
JP4178346B2 (en) * | 1998-12-18 | 2008-11-12 | 大阪瓦斯株式会社 | Ultrasonic vortex flowmeter |
JP4013426B2 (en) * | 1999-11-26 | 2007-11-28 | 日立工機株式会社 | centrifuge |
-
2001
- 2001-08-27 US US09/940,329 patent/US6531884B1/en not_active Expired - Lifetime
-
2002
- 2002-08-16 JP JP2003524019A patent/JP4519463B2/en not_active Expired - Fee Related
- 2002-08-16 EP EP02757209A patent/EP1423715B1/en not_active Expired - Lifetime
- 2002-08-16 CN CNB028170008A patent/CN1280639C/en not_active Expired - Lifetime
- 2002-08-16 WO PCT/US2002/026266 patent/WO2003019205A1/en active IP Right Grant
- 2002-08-16 DE DE60213258T patent/DE60213258T2/en not_active Expired - Lifetime
Cited By (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP1480023A1 (en) * | 2003-05-20 | 2004-11-24 | Endress + Hauser GmbH + Co. KG | Measurement device with apparatus for recognition of connected ultrasonic sensor |
US7255006B2 (en) | 2003-05-20 | 2007-08-14 | Endress +Hauser Gmbh + Co. Kg | Measuring instrument |
US20100045311A1 (en) * | 2008-08-20 | 2010-02-25 | Jaycee Howard Chung | Dual Electrical Current Sourcing-piezoresistive Material Self-Sensing (DEC-PMSS) System |
US11706990B2 (en) | 2017-05-24 | 2023-07-18 | HELLA GmbH & Co. KGaA | Method for calibrating at least one sensor |
CN110631646A (en) * | 2018-06-22 | 2019-12-31 | 微动公司 | Vortex flowmeter supporting flow instability detection |
EP3988950A1 (en) * | 2020-10-22 | 2022-04-27 | Yokogawa Electric Corporation | Diagnostic device, diagnostic method, and field device |
US20220128617A1 (en) * | 2020-10-22 | 2022-04-28 | Yokogawa Electric Corporation | Diagnostic device, diagnostic method, and field device |
WO2022128418A1 (en) * | 2020-12-17 | 2022-06-23 | Endress+Hauser Flowtec Ag | Vortex flow meter and method for testing a vortex flow meter |
Also Published As
Publication number | Publication date |
---|---|
CN1549929A (en) | 2004-11-24 |
DE60213258T2 (en) | 2007-06-06 |
DE60213258D1 (en) | 2006-08-31 |
JP4519463B2 (en) | 2010-08-04 |
WO2003019205A1 (en) | 2003-03-06 |
JP2005526228A (en) | 2005-09-02 |
CN1280639C (en) | 2006-10-18 |
EP1423715B1 (en) | 2006-07-19 |
US6531884B1 (en) | 2003-03-11 |
EP1423715A1 (en) | 2004-06-02 |
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