CA1194938A - Method and apparatus for determining the time interval between two electric pulses - Google Patents
Method and apparatus for determining the time interval between two electric pulsesInfo
- Publication number
- CA1194938A CA1194938A CA000423913A CA423913A CA1194938A CA 1194938 A CA1194938 A CA 1194938A CA 000423913 A CA000423913 A CA 000423913A CA 423913 A CA423913 A CA 423913A CA 1194938 A CA1194938 A CA 1194938A
- Authority
- CA
- Canada
- Prior art keywords
- pulses
- pulse
- time
- threshold value
- reaching
- 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.)
- Expired
Links
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R29/00—Arrangements for measuring or indicating electric quantities not covered by groups G01R19/00 - G01R27/00
- G01R29/02—Measuring characteristics of individual pulses, e.g. deviation from pulse flatness, rise time or duration
- G01R29/027—Indicating that a pulse characteristic is either above or below a predetermined value or within or beyond a predetermined range of values
- G01R29/0273—Indicating that a pulse characteristic is either above or below a predetermined value or within or beyond a predetermined range of values the pulse characteristic being duration, i.e. width (indicating that frequency of pulses is above or below a certain limit)
-
- G—PHYSICS
- G04—HOROLOGY
- G04F—TIME-INTERVAL MEASURING
- G04F10/00—Apparatus for measuring unknown time intervals by electric means
- G04F10/04—Apparatus for measuring unknown time intervals by electric means by counting pulses or half-cycles of an ac
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Investigating Or Analyzing Materials By The Use Of Ultrasonic Waves (AREA)
- Length Measuring Devices Characterised By Use Of Acoustic Means (AREA)
Abstract
ABSTRACT OF THE DISCLOSURE
To measure the pulse time interval of two electric or similar-formed pulses one uses two time measuring operations.
The first time measuring operation starts when the leading edge of the first pulse has reached an adjustable threshold value and ends when the leading edge of the second pulse has reached the same threshold value. The second time measuring operation starts when the falling edge of the first pulse has reached the threshold value and ends when the falling edge of the second pulse also arrives at the threshold value.
The measured quantities, determined digitally during the two time measuring operations, are then added. Subsequently the sum in divided by the factor two.
To measure the pulse time interval of two electric or similar-formed pulses one uses two time measuring operations.
The first time measuring operation starts when the leading edge of the first pulse has reached an adjustable threshold value and ends when the leading edge of the second pulse has reached the same threshold value. The second time measuring operation starts when the falling edge of the first pulse has reached the threshold value and ends when the falling edge of the second pulse also arrives at the threshold value.
The measured quantities, determined digitally during the two time measuring operations, are then added. Subsequently the sum in divided by the factor two.
Description
The present invention relates to a method and an apparatus for determining the time interval between two sym-metric or similar-formed electric pulses, triggering time-measuring operations when reaching adjustable threshold values resulting in measured values from which the pulse interval is determined.
A method and an apparatus of this kind are known.
According to this method, when exceeding the set threshold value by the first pulse a first time-measuring operation is started, which is Finished when falling below the same set threshold value by the falling-edge of the pulse. The second pulse triggers a second time-measuring operation passing off in the manner. A third time-measuring operation starts when the falling-edge of the first pulse is -Falling below the threshold value and ends on exceeding the threshold value by the leading edge of the second pulse. During the time-measuring operations periodic count pulses are summed up.
The frequency of the count pulses for the first two time-measuring operations is only half of that of the third time-measuring operation. The pulse interval is determined by summing up the count pulses obtained during the three time-measuring operations This known method is used in ultra-sonic material testing in order to determine sound periods, sound velocities, lengths or thicknesses of material by means of electric pulses generated sound impulses. Especially one can also de-termine more exactly intervals of successive back face echos.
31~
The present invention further develops a method and an apparatus of the above type in such a manner as to ob-tain a higher measuring accuracy, especially with pulses o-F rela-tively short period, at little expense.
Accorcling to the invention a -First period, lasting -from reaching the adjustable threshold value by -the leading edge the first pulse -t-ill reaching the adjus-table threshold value by the leading edge of the second pulse and a second period lasting -from reaching -the adjus-table threshold value by the falling edge oF the first pulse till reaching the ad-~ jus-table threshold value by the falling edge of the second I pulse are measured digitally; tha-t thereafter -the measured quantities of the period are summed up and subsequen-tly the sum is divided by two. This method does not require any measuring of pulse widths of the first and second pulses and can do without the -three time measuring operations. Two time measuring operations will suffice, each comprisin~ the duration of one pulse and the time interval between two pulses. Thus longer measuring times are made available as compared to the known rnethod. If in the known method and in the above described method one uses measuring apparatus of identical resolution capacity, then with the above described method there will be a smaller measuring error due to the longer measuring times. While with the known method the duration of the pulses is of great influence to the accuracy oF measurernen-t, this difficul-ty is removed with the above explained method.
Therefore -this method allows the determination of pulse time ; intervals in a larger range of dynamics.
1~
Prcferably the flrst and second periods are measured by surmniilg up periodic time pulses of equal frequency, Thus only one time pulse source is required. One can save a division of the sum of the count values by taking into account on evaluating the sum that the period of the time pulses is egual to two measuring units.
According to the invention, an apparatus for carrying out the above described method comprises a receiver for the pulses connected to comparators via gate circuits releasing the pulses to be measured, which comparators will change their binary output signal whenever the threshold value is reached by the leading edges of the pulses or from the falling edges; the output signals of the comparators each being con-nected to a release input of a counter; the counting inputs of the counters being charged by time pulses of a time gen-erator, and an adder and a dividing arrangement connected after the outputs of the counters. This arrangement excels by its small expense.
Desirably the dividing arrangement is a computer connected to the addin~ means. Preferably the receiver, the gate circuits, the comparators, the counters, the adding means and the computer are cornponents of an ultrasonic testing arrangement; the sound velocity is preset on the com-puter by means of an additional input, and an arrangement for the analog projection of wall thickness is connected to the computer via a digital-analog converter.
The present invention will be described in more detail by means of an embodiment shown in the accompanying drawings, wherein:
Pi~, 1 is a diagram of the progress in time of two successive pulses, 33~
Fig, 2 is a wiring diagram of an apparatus -for determining the pulse time interval of two successive pulses, and Fig. 3 is a diagram of the progress in time of signals generated in the apparatus according to Fig. 2.
2û
- 3a -33~
Fig. 1 shows two back face echo pulses RWl and RW2 generated by an ultrasonic testing apparatus after their transformation into corresponding electric signals. The back face echo pulses RW1 and RW2 are monitored as to an adjustable threshold value S. When the leading edge of the first back face echo pulse RWl reaches the threshold value S, then a first time measuring operation is started, whi.h is still continuing even a~ter the falling edge of said back face echo pulse RWl. The first time measuring operation is stopped each time when the leading edge of the second back face echo pulse RW2 has reached the threshold value 5. The duration of the first time measuring operation is indicated by an X in Fig. 1.
As soon as the falling edge of the back face echo pulse RW1 has reached the threshold value S, a second time measuring operation is started, lasting over the interval between the two pulses RW1 and RW2. The second time measuring operation, of which the duration is marked by an y in Fig. 1, is stopped by the falling edge of the second back face echo pulse RW2 when its level has reached the threshold value 5.
The width of the first face echo pulse RW1 at the level of the threshold value S is marked 2a in Fig. 1. Accordingly the width of the second back face echo pulse RW2 is marked 2b. The time interval, marked t~ in Fig. 1, between the averages Ml and M2 of the two back face echo pulses RWl and RW2 results after following relation from the measured quantities received during the time measuring operations for the respective duration of x and y:
This re`Lation follows therefrom that it is x = a -~ t - b and y = -a + tm 3~
During the two measuring operations, digital measurements are taken of the values x and y. Subsequently the sum of the measured quantities x and y is computed. Thereafter this sum is divided by the factor 2.
According to the above explained principle one can measure the pulse intervals of symmetric or similar-formed pulses. For example, the pulse transit times of multiple echoes can be recorded.
The time operations each last for the duration of x and y. Although the respective duration of x and y includes likewise the pulse width of RWl and RW2, it is not necessary to measure this width separately. Especially with short pulses RWl and RW2, measuring operations can be dropped that differ by dimensions as far as the measuring time is concerned. lf the pulse intervals tm are computed from measured values differing by dimensions as to the dig measuring time, then the measuring error being connected with the short measuring time is determining the measuring error of the result. With the above explained measuring method, however, there will be no essential differences between the durations o~ x and y. Therefore the employed measuring instruments can be optimally exploited with respect to the approved measuring error of the result. Especially the pulse intervals of small pulses can likewise be determined with great accuracy.
In the following an d pparatus for carrying out the above explained measuring method is described. This apparatus serves to measure the time interval of reflections of the beat from the back surface in ultrasonic testing.
An ultrasonic testing arrangement comprises a pulse generator (not shown) and an ultrasonic receiver 10. The pulse sender and the ultrasonic receiver are connected to the testing head (not shown) of the ultrasonic testing apparatus. The output of the ultrasonic receiver 3~
is connected to gate circuits 12. The gate circuits 12 are stopping out specified si~nals existing at the output of the receiver 10. These signals are such of which the interval shall be measured, e.g. the first two back face echo pulses RWl and RW2. The opening time of the gate circuits 12 is especially adapted to that period in which the pulses to be measurcd are expected. Two comparators 14, 16 are connected to the gate circuits 12. The comparators 14, 16 are furthcrmore connected to arrangements 18, 20 by which the threshold value S is exceeded each time.
The comparator lL is designed in such a manner that it will respond to the leading edge of the first back surface echo pulse RWl when the threshold value S is reached, and thereby at its output a binary signal is changing its value. Furthermore the comparator 14 responds to the leading edge of the second back face echo pulse RW2 insofar as its output signal is again grading into the other binary value.
The comparator 16 shows a similar behavior. ~nlike the comparator 14 it responds to the falling edge of the first back face echo pulse RWl when the threshold value S is reached, and thereby its output changes the binary value of the output signal. Further the comparator 16 responds to the falling edge of the second back face echo pulse RW2 when reaching the threshold value 5, and thereby changes again the binary value of its output signal.
The output slgnals of the comparator lL, 16 as control signals, each are feeding corresponding inputs of counters 22, 2L of which the counting inputs alltogether are connected to a time generator 26, delivering time pulses of a constant frequency. The outputs of the two counters 22, 24 each are connected to one of the summing-up inputs of an adder 23 after which a computing machine 30, e.g. a microcomputer, is connected. Via an input 32, additional date, e.g.
the sound velocity of the material to be tested, are fed to the computer 30. The computer 30 is feeding a digital output 34 and further an analog output 38 via a digital-analog converter 36.
~Y ~3~
In the ultrasonic testing, at the receiver 10 at the original pulse from the ultrasonic transmitter one receives the entrance echo 40 into the test piece, the first back face echo pulse RWl, the second back face echo pulse RW2 and the third back surface echo pulse RW3.
Additional back face echo pulses are not shown in Fig. 3.
A control logic (not shown), which e.~. is realized by the computer 30, allows the ~ate circuits 12 a stopping duration 42 during which the back face echo pulses RWl and RW2, via the gate connections 12, can reach the comparator 14 and 16. Therefore only the first two back face echo pulses will be subjected to the measuring.
When the threshold value S has been reached by the first back face echo pulse RWl, a binary control signal 44 appears at the output of the comparator, having e.g. the binary value "1". The control signal 44 will end as soon as the second back face echo pulse RW2 has reached the threshold value 5. The control signal 44 will drop thereby in that the output signal of the comparator 14 is taking the binary value "O". As soon as the falling edge of the back face echo pulse RWl has reached the threshold value S, a control signal 46 appears at the output of the comparator 16, which signal having likewise e.g. the binary value "1". With the returning of the second back face echo pulse RW2 to the threshold value S after having passed over the peak value, the control signal 46 will end in -that the output of the comparator 16 is grading into the other binary value.
Durin~ their duration, the signals 44, 46 each are opening the counters 22, 24 for the time pulses 48, 50 of the time generator 26.
The frequency of the time pulses is within the megacycle range. The contents of the counters 22, 24 e.g. can be effaced in the leading edge of the control signals 44, 46 and subsequently be released for the time pulses.
3~
The contents of the counters 22. 24, by the falling edge of the signals 4L, L6 are tra nsmitted to the adding machine 28 which makes up the sum of the counter contents. The computer receives the sum of the counter contenls from the adder 28 and from that sum, after d!vidin~ it by the factor 2, determines the pulse interval tm between the back face echo pulses RWl and RW2. By means of the sound veh~.ity a!lowecl via the input 32, the wall thickness of the test p~ece is cletermined in the computer 30 and digitally put out via the channel 34. I`he digital-analog converter 36 produces an analog value cf the wall thickness, which e.g. can be shown on an indicator instrument .
A method and an apparatus of this kind are known.
According to this method, when exceeding the set threshold value by the first pulse a first time-measuring operation is started, which is Finished when falling below the same set threshold value by the falling-edge of the pulse. The second pulse triggers a second time-measuring operation passing off in the manner. A third time-measuring operation starts when the falling-edge of the first pulse is -Falling below the threshold value and ends on exceeding the threshold value by the leading edge of the second pulse. During the time-measuring operations periodic count pulses are summed up.
The frequency of the count pulses for the first two time-measuring operations is only half of that of the third time-measuring operation. The pulse interval is determined by summing up the count pulses obtained during the three time-measuring operations This known method is used in ultra-sonic material testing in order to determine sound periods, sound velocities, lengths or thicknesses of material by means of electric pulses generated sound impulses. Especially one can also de-termine more exactly intervals of successive back face echos.
31~
The present invention further develops a method and an apparatus of the above type in such a manner as to ob-tain a higher measuring accuracy, especially with pulses o-F rela-tively short period, at little expense.
Accorcling to the invention a -First period, lasting -from reaching the adjustable threshold value by -the leading edge the first pulse -t-ill reaching the adjus-table threshold value by the leading edge of the second pulse and a second period lasting -from reaching -the adjus-table threshold value by the falling edge oF the first pulse till reaching the ad-~ jus-table threshold value by the falling edge of the second I pulse are measured digitally; tha-t thereafter -the measured quantities of the period are summed up and subsequen-tly the sum is divided by two. This method does not require any measuring of pulse widths of the first and second pulses and can do without the -three time measuring operations. Two time measuring operations will suffice, each comprisin~ the duration of one pulse and the time interval between two pulses. Thus longer measuring times are made available as compared to the known rnethod. If in the known method and in the above described method one uses measuring apparatus of identical resolution capacity, then with the above described method there will be a smaller measuring error due to the longer measuring times. While with the known method the duration of the pulses is of great influence to the accuracy oF measurernen-t, this difficul-ty is removed with the above explained method.
Therefore -this method allows the determination of pulse time ; intervals in a larger range of dynamics.
1~
Prcferably the flrst and second periods are measured by surmniilg up periodic time pulses of equal frequency, Thus only one time pulse source is required. One can save a division of the sum of the count values by taking into account on evaluating the sum that the period of the time pulses is egual to two measuring units.
According to the invention, an apparatus for carrying out the above described method comprises a receiver for the pulses connected to comparators via gate circuits releasing the pulses to be measured, which comparators will change their binary output signal whenever the threshold value is reached by the leading edges of the pulses or from the falling edges; the output signals of the comparators each being con-nected to a release input of a counter; the counting inputs of the counters being charged by time pulses of a time gen-erator, and an adder and a dividing arrangement connected after the outputs of the counters. This arrangement excels by its small expense.
Desirably the dividing arrangement is a computer connected to the addin~ means. Preferably the receiver, the gate circuits, the comparators, the counters, the adding means and the computer are cornponents of an ultrasonic testing arrangement; the sound velocity is preset on the com-puter by means of an additional input, and an arrangement for the analog projection of wall thickness is connected to the computer via a digital-analog converter.
The present invention will be described in more detail by means of an embodiment shown in the accompanying drawings, wherein:
Pi~, 1 is a diagram of the progress in time of two successive pulses, 33~
Fig, 2 is a wiring diagram of an apparatus -for determining the pulse time interval of two successive pulses, and Fig. 3 is a diagram of the progress in time of signals generated in the apparatus according to Fig. 2.
2û
- 3a -33~
Fig. 1 shows two back face echo pulses RWl and RW2 generated by an ultrasonic testing apparatus after their transformation into corresponding electric signals. The back face echo pulses RW1 and RW2 are monitored as to an adjustable threshold value S. When the leading edge of the first back face echo pulse RWl reaches the threshold value S, then a first time measuring operation is started, whi.h is still continuing even a~ter the falling edge of said back face echo pulse RWl. The first time measuring operation is stopped each time when the leading edge of the second back face echo pulse RW2 has reached the threshold value 5. The duration of the first time measuring operation is indicated by an X in Fig. 1.
As soon as the falling edge of the back face echo pulse RW1 has reached the threshold value S, a second time measuring operation is started, lasting over the interval between the two pulses RW1 and RW2. The second time measuring operation, of which the duration is marked by an y in Fig. 1, is stopped by the falling edge of the second back face echo pulse RW2 when its level has reached the threshold value 5.
The width of the first face echo pulse RW1 at the level of the threshold value S is marked 2a in Fig. 1. Accordingly the width of the second back face echo pulse RW2 is marked 2b. The time interval, marked t~ in Fig. 1, between the averages Ml and M2 of the two back face echo pulses RWl and RW2 results after following relation from the measured quantities received during the time measuring operations for the respective duration of x and y:
This re`Lation follows therefrom that it is x = a -~ t - b and y = -a + tm 3~
During the two measuring operations, digital measurements are taken of the values x and y. Subsequently the sum of the measured quantities x and y is computed. Thereafter this sum is divided by the factor 2.
According to the above explained principle one can measure the pulse intervals of symmetric or similar-formed pulses. For example, the pulse transit times of multiple echoes can be recorded.
The time operations each last for the duration of x and y. Although the respective duration of x and y includes likewise the pulse width of RWl and RW2, it is not necessary to measure this width separately. Especially with short pulses RWl and RW2, measuring operations can be dropped that differ by dimensions as far as the measuring time is concerned. lf the pulse intervals tm are computed from measured values differing by dimensions as to the dig measuring time, then the measuring error being connected with the short measuring time is determining the measuring error of the result. With the above explained measuring method, however, there will be no essential differences between the durations o~ x and y. Therefore the employed measuring instruments can be optimally exploited with respect to the approved measuring error of the result. Especially the pulse intervals of small pulses can likewise be determined with great accuracy.
In the following an d pparatus for carrying out the above explained measuring method is described. This apparatus serves to measure the time interval of reflections of the beat from the back surface in ultrasonic testing.
An ultrasonic testing arrangement comprises a pulse generator (not shown) and an ultrasonic receiver 10. The pulse sender and the ultrasonic receiver are connected to the testing head (not shown) of the ultrasonic testing apparatus. The output of the ultrasonic receiver 3~
is connected to gate circuits 12. The gate circuits 12 are stopping out specified si~nals existing at the output of the receiver 10. These signals are such of which the interval shall be measured, e.g. the first two back face echo pulses RWl and RW2. The opening time of the gate circuits 12 is especially adapted to that period in which the pulses to be measurcd are expected. Two comparators 14, 16 are connected to the gate circuits 12. The comparators 14, 16 are furthcrmore connected to arrangements 18, 20 by which the threshold value S is exceeded each time.
The comparator lL is designed in such a manner that it will respond to the leading edge of the first back surface echo pulse RWl when the threshold value S is reached, and thereby at its output a binary signal is changing its value. Furthermore the comparator 14 responds to the leading edge of the second back face echo pulse RW2 insofar as its output signal is again grading into the other binary value.
The comparator 16 shows a similar behavior. ~nlike the comparator 14 it responds to the falling edge of the first back face echo pulse RWl when the threshold value S is reached, and thereby its output changes the binary value of the output signal. Further the comparator 16 responds to the falling edge of the second back face echo pulse RW2 when reaching the threshold value 5, and thereby changes again the binary value of its output signal.
The output slgnals of the comparator lL, 16 as control signals, each are feeding corresponding inputs of counters 22, 2L of which the counting inputs alltogether are connected to a time generator 26, delivering time pulses of a constant frequency. The outputs of the two counters 22, 24 each are connected to one of the summing-up inputs of an adder 23 after which a computing machine 30, e.g. a microcomputer, is connected. Via an input 32, additional date, e.g.
the sound velocity of the material to be tested, are fed to the computer 30. The computer 30 is feeding a digital output 34 and further an analog output 38 via a digital-analog converter 36.
~Y ~3~
In the ultrasonic testing, at the receiver 10 at the original pulse from the ultrasonic transmitter one receives the entrance echo 40 into the test piece, the first back face echo pulse RWl, the second back face echo pulse RW2 and the third back surface echo pulse RW3.
Additional back face echo pulses are not shown in Fig. 3.
A control logic (not shown), which e.~. is realized by the computer 30, allows the ~ate circuits 12 a stopping duration 42 during which the back face echo pulses RWl and RW2, via the gate connections 12, can reach the comparator 14 and 16. Therefore only the first two back face echo pulses will be subjected to the measuring.
When the threshold value S has been reached by the first back face echo pulse RWl, a binary control signal 44 appears at the output of the comparator, having e.g. the binary value "1". The control signal 44 will end as soon as the second back face echo pulse RW2 has reached the threshold value 5. The control signal 44 will drop thereby in that the output signal of the comparator 14 is taking the binary value "O". As soon as the falling edge of the back face echo pulse RWl has reached the threshold value S, a control signal 46 appears at the output of the comparator 16, which signal having likewise e.g. the binary value "1". With the returning of the second back face echo pulse RW2 to the threshold value S after having passed over the peak value, the control signal 46 will end in -that the output of the comparator 16 is grading into the other binary value.
Durin~ their duration, the signals 44, 46 each are opening the counters 22, 24 for the time pulses 48, 50 of the time generator 26.
The frequency of the time pulses is within the megacycle range. The contents of the counters 22, 24 e.g. can be effaced in the leading edge of the control signals 44, 46 and subsequently be released for the time pulses.
3~
The contents of the counters 22. 24, by the falling edge of the signals 4L, L6 are tra nsmitted to the adding machine 28 which makes up the sum of the counter contents. The computer receives the sum of the counter contenls from the adder 28 and from that sum, after d!vidin~ it by the factor 2, determines the pulse interval tm between the back face echo pulses RWl and RW2. By means of the sound veh~.ity a!lowecl via the input 32, the wall thickness of the test p~ece is cletermined in the computer 30 and digitally put out via the channel 34. I`he digital-analog converter 36 produces an analog value cf the wall thickness, which e.g. can be shown on an indicator instrument .
Claims (6)
1. A method for determining the time interval between two symmetric, similar-formed pulses, triggering time-measuring operations on reaching adjustable threshold values resulting in measured quantities from which the pulse interval is found, in which method the first period lasting from reaching the adjustable threshold value by the leading edge of the first pulse value till reaching the adjustable threshold value by the leading edge of the second pulse, and the period lasting from reaching the adjustable threshold value by the falling edge of the first pulse till reaching the adjustable threshold value by the falling edge of the second pulse, are measured digitally;
thereafter the measured quantities of the periods are summed up; and subsequently this sum is divided by two.
thereafter the measured quantities of the periods are summed up; and subsequently this sum is divided by two.
2. A method according to claim 1, in which the first period and the second period are measured by summing up periodic time pulses of equal frequency.
3. A method according to claim 1 or 2, in which the pulses are sequential back face echo pulses in the ultra-sonic testing of work pieces.
4. An apparatus for determining the time interval between two symmetric, similar-formed pulses, triggering time-measuring operations on reaching adjustable threshold values resulting in measured quantities from which the pulse inter-val is found, comprising a receiver for the pulses connected to comparators, via gate circuits releasing the pulses to be measured, which comparators each time on reaching the threshold value of those edges of the pulses either leading edges or falling edges, change their binary output signal;
the output signals of the comparators each being connected to a release input of a counter; the counting inputs of the counters being charged by time pulses of a time generator, and an adding means and a dividing arrangement connected after the outputs of the counters.
the output signals of the comparators each being connected to a release input of a counter; the counting inputs of the counters being charged by time pulses of a time generator, and an adding means and a dividing arrangement connected after the outputs of the counters.
5. An apparatus according to claim 4, in which the dividing arrangement is a computer connected to the adding means.
6, An apparatus according to claim 5, in which the receiver, the gate circuits, the comparators, the counters, the adding means and the computer are components of an ultra-sonic testing arrangement; the sound velocity is preset on the computer by means of an additional input, and an arrange-ment for the analog projection of wall thickness is connected to the computer via a digital-analog converter.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE19823210436 DE3210436C2 (en) | 1982-03-22 | 1982-03-22 | Method and device for determining the time interval between two electrical pulses |
| DEP3210436.7 | 1982-03-22 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1194938A true CA1194938A (en) | 1985-10-08 |
Family
ID=6158935
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000423913A Expired CA1194938A (en) | 1982-03-22 | 1983-03-18 | Method and apparatus for determining the time interval between two electric pulses |
Country Status (4)
| Country | Link |
|---|---|
| EP (1) | EP0091563B1 (en) |
| JP (1) | JPS58171123A (en) |
| CA (1) | CA1194938A (en) |
| DE (1) | DE3210436C2 (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE3446837A1 (en) * | 1984-12-21 | 1986-06-26 | Institut Dr. Friedrich Förster Prüfgerätebau GmbH & Co KG, 7410 Reutlingen | METHOD AND DEVICE FOR ACCURELY DETERMINING THE TIME DISTANCE OF TWO ELECTRICAL PULSES |
| DE19602810A1 (en) * | 1996-01-26 | 1997-07-31 | Siemens Ag | Method and device for measuring the transit time of an electrical, electromagnetic or acoustic signal |
| DE19948892C2 (en) * | 1999-10-11 | 2002-07-18 | Asm Automation Sensorik Messte | Pulse detector and method for the detection of sinusoidal pulses |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB1470660A (en) * | 1974-11-15 | 1977-04-21 | British Aircraft Corp Ltd | Time interval measurement |
| DE2607187C3 (en) * | 1976-02-23 | 1986-07-10 | Krautkrämer GmbH, 5000 Köln | Method for measuring the time interval between two electrical pulses |
| DE2923963C2 (en) * | 1979-06-13 | 1986-03-27 | Endress U. Hauser Gmbh U. Co, 7867 Maulburg | Method for pulse spacing measurement and arrangement for carrying out the method |
-
1982
- 1982-03-22 DE DE19823210436 patent/DE3210436C2/en not_active Expired
-
1983
- 1983-03-10 EP EP19830102343 patent/EP0091563B1/en not_active Expired
- 1983-03-18 JP JP58044553A patent/JPS58171123A/en active Pending
- 1983-03-18 CA CA000423913A patent/CA1194938A/en not_active Expired
Also Published As
| Publication number | Publication date |
|---|---|
| DE3210436A1 (en) | 1983-09-29 |
| EP0091563A1 (en) | 1983-10-19 |
| DE3210436C2 (en) | 1984-01-05 |
| JPS58171123A (en) | 1983-10-07 |
| EP0091563B1 (en) | 1986-02-26 |
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