GB2227320A - Apparatus for measuring parameters of moving ferromagnetic articles - Google Patents
Apparatus for measuring parameters of moving ferromagnetic articles Download PDFInfo
- Publication number
- GB2227320A GB2227320A GB8901041A GB8901041A GB2227320A GB 2227320 A GB2227320 A GB 2227320A GB 8901041 A GB8901041 A GB 8901041A GB 8901041 A GB8901041 A GB 8901041A GB 2227320 A GB2227320 A GB 2227320A
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- output
- magnetically sensitive
- moving
- sensitive elements
- clock pulse
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N27/00—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means
- G01N27/72—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating magnetic variables
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- Chemical & Material Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Electrochemistry (AREA)
- Physics & Mathematics (AREA)
- Health & Medical Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- Analytical Chemistry (AREA)
- Biochemistry (AREA)
- General Health & Medical Sciences (AREA)
- General Physics & Mathematics (AREA)
- Immunology (AREA)
- Pathology (AREA)
- Measuring Magnetic Variables (AREA)
- Investigating Or Analyzing Materials By The Use Of Magnetic Means (AREA)
Description
1 APPARATUS FOR MEASURING PARAMETERS OF MOVING PERROMAGNETIC ARTICLES The
invention relates to monitoring the properties of metals and alloyst and more particularly it relates to apparatus for measuring physical and mechanical parameters of ferromagnetic articles.
The invention can be employed for monitoring the physical and mechanical properties (such as hardness ultimate strength, relative elongation, coercive force, etc.) of rolled plate and sheet stock.
The invention can be used to the utmost effectiveness for non-destructive monitoring and inspection of physical and mechanical parameters of rolled sheet and plate steel stock in metallurgical production, as well as of parameters reDresentative of the necessity of thermal treatment of such stock# It Is an object of the present Invention to create an apparatus, for measuring parameters of moving ferromagne- tic articles t amprL-kg a circuit providing for introduction of new components and their relationships with other components of the apparatus, for enhancing timeand temperaturerelated stability and linearity of characteristics of the apparatusq and also for stepping up its resistance to In- fluence of external magnetic fieldsq thus ensuring higher accuracy and stability of measurements for upgraded quality of the rolled stock in existing metal-rolling technoloSies.
This object is attained in an apparatus for measuring parameters of moving ferromagnetic articles, comprising a series connection of a clock pulse generator and a generator of current pulses having contiected to one output thereof two magnetizing members arranged at two opposite sides of an article under inspection, two memory units having their respective control inputs connected to the first output of the clock pulse generaor and their respective outputs connected to the input of a unit for measuring the geometric mean of signals, having its output connected to a recorder, two circuits each including a series connection with a magnetically sensitive element and a peak detector having its reset Input connected to the second output of the generator of current pulses, the two magnetically sensitive elements being at two opposite sides of the article under inspection. which apparatus,-in accordance with the present invention, further comprises two inverters having their respective inputs connected to the outputs of the respective magnetically sensitive elements. and two circuits each including a series connection of an Integrator and a reference source of a magnetic fields situated In the area of the respective one of the two magnetically sensitive elements and having its output connected to the data input of the respective memory unit, the first data Input of each integrator being connected with the output of the respective peak detectors the second data inptit of each Integrator being connected with 23 the output of the respective inverter. the react Inputs of the integrators and the control Inputs of the peak detectors being connected to the other output of the clock pulse generator.
1 It is expedient to select the pulse repetition period of the clock pulse generator from a condition:
21 e- Tl 7 where 1 is the spacing of the pair of magnetizing mezibers from the pair of magnetically sensitive elements, V Is the speed of the moving article under inspection, and T is the pulse reDetition period of the clock pulse generator.
With a preferred apparatus for measuring parameters of moving ferromagnetic articles being.constructed in accordance with the present invention$ provisions are made for expanding the dynamic range of measurements and enhancing the accuracy and stability of measurements owing to elimination of dependence of the outcome of measurements on time-- and temperature-related instability and non-linearity of the characteristics of the magnetically responsive elements.
Following hercinbelow is a description of an embodiment of the invention by way of example udth reference being M36. to the accompanying act of drawingay whereini
FIG. 1 Is a functional block diagram of an apparatus for measuring parameters of moving ferromagnetic articlesq embodying the inventionj FIG. 2 illustrates the operation of the apparatus of FIG. 1 by plotting corresponding signals versua time.
The apparatus for measuring parameters of moving ferromagnetic articles comprises magnetically sensitive elements 1 and 2 disposed to two opposite sides of the mov ing article 3 under inspection, a clock pulse generator 4 connected with a f,.enerator 5 of current pulses (a sur6e current generator), having one of its outputs connected with magnetizing members 6 and 7 arranged symmetrically to two opposite sides of the moving article 3 under inspection. The magnetically sensitive elements 1 and 2 are arranged at the same two opposite sides of the moving article 39 downstream of the magnetizing members 6 and 7 in the direction of the progress of the article 39 shown in FIG. 1 with arrow A.
The respective outputs of the magnetically sensitive elements 1 and 2 are connected through respective peak detectors 8 and 99 integrators 10 and 11, reference sources 12 and 13 of magnetic fields and memory units 14 and 15 to the respective inputs of a unit 16 for measuring the geometric mean of signals, having its output connected to a record- er or monitor 17.The reference sources 12 and 13 of magnetic field are arranged in the areas of the respective magnetically sensitive elements 1 and 2. The reset inputs of the peak detectors 8 and 9 are connected to the generator 5 of current pulses, and tile control inputs of the memory units 14 and 15 are connected to the other OUtDUt Of the clock pulse generator.
Inverters 18 and 19 are connected between the respective outputs of the magnetically sensitive elements 1 and 2 and the respective other inputs of the Integrators 10 and 11. The reset Inputs of the integrators 10 and 11 and the control inputs of the peak detectors 8 and 9 are connected to the other output of the clock pulse generator 4. FIG. 2 Illustrates the operation of the disclosed appara- tus by plotting corresponding signals versus time thus show- 11 ing the sequence of the passage of the signals in the main component units of the aPparatus.
The following symbols and numerals are used in FIG. 2: 209 21, 22 signals from the clock pulse generator at corresponding points; IM current through the magnetizing members 6 and 7; UM - output signal of the magnetically reSDOn- sive elements 1 and 2; U 1. - ?D - outDut signal of the peak de tectors 8 and 9; URS - output signal of the reference sources 12 and 13 of magnetic field; UMU - output signal of the memory units 14 and 151 UV- - output signal of the unit 16 measuring the t;eometric mean of signals.
The apparatus for measuring parameters of moving fer-. romagneticarticles, embodying the invention, operatess as f ollov;s.
DePending on the speed of the motion of the article 3 under inspection. the clock pulse generator 4 provides-at its outputs 20 and 21 pulse trains illustrat.ed undgr the cor responding numerals in FIG. 2. The trailing edge of a pulse coming from the output 20 of the clock pulse generator triggers the current pulse generator 5 upon its arrival thereat, whereby the generator 5 produces a corresponding current pulse which is sent to the magnetizing members 6 and 7 which are symmetrically disposed on opposite sides of the moving article 3 under inspection. In this manner. the opposite sides of the moving ferromagnatio.article 3 receive magne tic marks carrying information -about the mechanical properties of the article 3 (by influencing its magnetization according to known laws). Simultaneously with the passage of the current pulse through the magnetizing members 6 and 79 a current pulse from the output 22 of the generator 5 of current pulses is sent to the reset inputs of the peak detectors 8 and gy resetting them. Thus, during the period 2. - 21 (FIG. 2) when the high (unit) voltage level is set at the output 21 of the clock pulse generator 2lg the Integrators 10 and 11 are reset and disabled. and the peak detectors 8 and 9 are prepared for operation.
As tile article 3 under inspection progresses from the magnetizing members 6 and 7 towards tile magnetically sensitive elements 1 and 2 disposed on the same two opposite sides of the moving article 3 downstream of the magnetizing members 6.and 7, tile magnetic marks applied by the latter onto the opposite sides of the article 3 make the elements 1 and 2 respond by generating at their respective outputs electric signals proportional to the gradient of the normal component of the intensity of the field of residual magnetization. These signals are detected by the peak detectors 8 and 91 respectively.
Within the time Interval Tl - 112 when the low (zero) voltage level Is set at the output 21 of the clock pulse generator 41 the integrators 10 and 11 are unblocked through their respective reset inputs. and the peak detectors 8 and 9 are set by their respective control in-ruts Into a state where their output signal is unaffected by the input signal, i.e. where their output voltage is maintained at the level of the preceding detected signal. This output volt- Z 1 age of the peak detectors 8 and 9 is sent to the respective first data inputs of the integrators 10 and 11, causing a grov,-th of their output signals. Consequently, the reference sources 12 and 13 of magnetic fields induce in the respec5 tive areas of the magnetically sensitive elements 1 and 2 maGnetic fields of....,hich the gradient of the normal component is directed identically with the gradient of the normal component of the intensity of the field of residual magnetization. Meanwhile the output signals of the'magnetically sensitive elements 1 and 2 are sent through the respective inverters 18 and 19 to the resD^ctive other data inputs of the integrators 10 and 11.
As the gain factors of the Integrators 10 and 11 are high (about 105)l their output voltages cease varying when the signals at the two data Inputs become practically equal by their modulus (i.e. by their absolute values). This is tne case when tne gradient of the normal component of the magnetic field created by.the reference sources 12 and 13 bec.omes equal to the amplitude value of the gradient of the normal component of the intensity of the field of residual magnetization, as the time interval TO - T 1 is selected so that the magnetic marks applied onto the opposite sides of the moving article 3 under Inspection should have travelled beyond the area of response of the magnetically 25 sensitive elements 1 and 2.
The output signals of the reference sources 12 and 13 of magnetic fieldg proportional to the gradient of the normal component of the magnetic field they inducey are fed to the data Inputs of the respective memory units 14 and 15.
Upon the appearance of the leading edge of each successive pulse at the output 20 of the clock pulse generator 4, the output signals of the reference sources 12 and 13 are written into the respective memory units 14 and 15. The output signals of the memory units 14 and 15 are fed to the respective Inputs of -the unit 16 for measuring the geometric mean of these signals, causing an output signal of the unit 16 to be either recorded or displayed, correspondingly. by the recorder or monitor 17. Upon the appearance of the trailing edge of each of &e p fises, at the output 20 of the clock pulse generator 4, the above described operating cycle Is repeated. The record or reading of the recorder or monitor 17 Is used for assessing the corresponding parameters defining the me- chanical or physical properties of the article 3 under InsDection.
With the information appearing at the outputs of the reference sources 12 and 13 of magnetic fields being wkitten into the respective memory units 14 and 15 with the ar- rival of the leading edge of a pulse at the output 20 of the clock pulse generator 4. and the generator 5 of current po being triggered by the tralling edge of this pulse of the clock pulse generator 4g the writing of the Information into the memory units 14 and 15 positively takes place before commencing the application of " next amcessive pair of magnetic marks upon the moving article 3 under inspection. Directly within the Instants of appli cation of these marks, the peak detectors 8 and 9 are dis- abled by their reset inputs receiving a pulse from the generator 5 of current pulses. Thus, the recording of an interference signal caused by the application of magnetic marks onto the article 3 under inspection is positively precluded.
The period of repetition of pulses of the clock pulse generator 4 Is preferably selected from a condition:
21 < T v- where 1 is the spacing of the pair of magnetizing members and the pair of magnetically sensitive elements In the direction of the travel of the article under inspection; is the speed of the motion of the article under inspection; and T is the,.,.pulse repetition period of the clock pulse generator.
In the preferred embodiment of the disclosed apparatus, the adherence to this condition enhances the credibility of the performance of the apparatus: if this require- ment Is not met, in the instant of applying the rext successive pair of magnetic marks onto the moving article 3 under In spection within the period Tl - T 2 (FIG. 2), one of the pre ceding pairs of marks would be in the area of.response of the magnetically sensitive elements 1 and 29 while the peak detectors 8 and 9 would be currently disabled by the reset pulse coming from the output of the generator 5 of current pulses# causing an erroneous reading of the re corder or monitor 17.
v An apparatus constructed in accordance with the invention is practidally unaffected by the influence cf external permanent magnetic fields, owing to these fields equally affecting the magnetically sensitive elements 1 and 2 within the ti.;.me intervals of detection of signals caused by marks applied upon the moving article 3 under inspection and within the periods of operation of the reference snurces 12 and 13 of magnetic fields.
Q The incorDoration in the disclosed apparatus of the two inverters 18 and 19 and of the two circuits each including a series connection of the Integrator 10 or 11 and of the reference source 12 or 13 of a magnetic fieldg with their disclosed connections with the other components of the apparatus,, enhances the accuracy and stability of mea- surements and provides for expanding the dynamic measurement rangeg as the magnetically sensitive elements 1 and 2 of the disclosed apparatus are actually employed for determining the equality of the gradient of the field of residual magnetization and of the gradient of the normal compo- nent of the magnetic field of the respective reference source 12 and 13. With the time intervals between the measurements of the gradient of the normal component of the fields of the reference sources 12 and 13 beingrelatively short (from fractions of a second to several seconds)q the gain factors of the magnetically sensitive elements (i.e. the character of their response) would not vary within such periods. Therefore. the accuracy and stability of measurements Is defined by the accuracy of comparison as well as by the V 3 time- and temperature-related stability of the reference tl sources 12 and 13,.,..hereas the linearity of measurement would be determined by the linearity of these standard reference sources 12 and 13. With the gain factor of the measurement path of the apparatus as high as 105, the comparlson error would not exceed 0.01 %. The stability of the reference sources which are preferably standard coreless coils is dependent on the permanence of their geo,--etrical shape, all but unaffected by either time or temperature.
1,:&.'oreove-.Y-, the field and Its gradient produced by such sources are linearly dependent on the current flowing through their coils.
The testing of a prototype of the disclosed a paratus p has shown that the relative error in measuring the gradient of the residual magnetization field is viellwithin 1 %.
Thus, the disclosed apparatus with its enhanced timeand te=peraturerelated stability and linearity of the characteristics. with the stepped up resistance of its performance to the Influence of external magnetic fields, pro- vides for upgrading the accuracy and stability of measurements and expanding the dynamic range of measurements, for higher quality of the rolled stock in existing metal-rolling, technologies..
The components of the die- closed apparatus, referred to in the preceding description by corresponding numerals will now be further described:
1, 2 - magnetically sensitive elements capable of converting the gradient of the normal component of a magnetic field into an electric signal. They can be Hall generators, r- acnetoresistors and other suitable known devices assoclated with appropriate power supply systems and capable of issuing a data signal in the required form;
3 - a moving article under inspection, e.g. rolled steel band, sheet or plate stock, etc.; 4 - a clock pulse generator operated to synchronize thhe operation of the apparatus, as a whole, and oil its co=onents. It can employ the frequency of the po,.,;er sup- ply mains, processed by appropriate scaling logical cir- cuits, or else it can include a variable oscillator in association with appropriate logical scaling circuits; 5. a generator of current pulses or a surgre current generator, operable for sending pulses of electric current through the magnetizing members. It can be a charged-dis- charged device including a storage capacitor as the energy accumulator; 6, 7 - magnetizing elements operable for providing a pulsed magnetic field for applying magnetic marks onto the article =der Inspection. They are preferably in the form of solenoids;
89 9 - peak detectors operable for detecting the o utput signals of the magnetically sensitive elements. They should be complete with reset (to zero) inputs and control inputs inhibiting variation of the output signal of the detector, which in the simplest version is the input of an electronic gate connected In series with the detecting diode; 1 1 - 13 10, 11 - integrators for meeting the condition of C> J.
equality of the measured gradient of a magnetic field and the gradient of the magnetic field produced by the reference source. Each integrator has two data inputs and one reset input. The integrators can be LUller integrators with the capacitor in the negative feedback connection of the operational amplifier; 12, 13 reference sources of magnetic fields incorcorated to produce a gradient of the normal component
1C) of a --asnetic field in the area of response of the respective =agnetically sensitive element. They can be in the form of Waniell rings serially connected with a resistor, the input being the free output of the Laxwell rings, and the output being the point of connection of the resistor with the other output of the rings, the other lead of the resistor being connected to the common wire. The signal derived from the resistor Is proportional to the current through the Maxwell rings, and, hence, to the gradient of the magnetic field produced thereby; 20 149 15 - memory units for temporarily memorizing an output signal, of ang suitable structure including a data input and control (read/write) Inputs; 16 - a unit for measuring the geometric mean of the output signals of the memory units. It Is a computing de- vice, either analog or digitall e.g. Incorporating Integrated microprocessor circuitry; 17 - a recorder or monitor for either recording or displaying the outcome of measurements, or both. It can be any suitable pen recorder, digital voltmeter, etc.; 18, 19 - inverters operable for inverting the output signals of the magnetically sensitive elements, of any commonly known circultry with the use of operational am- plifiers. - 1
Claims (5)
1. An apparatus for measuring parameters of moving ferromagnetic articles, comprising a pair of magnetising members disposed on mutually opposite sides of a path of said moving articles; a pair of magnetically sensitive elements disposed on mutually opposite sides of said path. and displaced from the magnetising members in a direction of forward movement of the moving ferromagnetic articles; means for processing signals detected by the magnetically sensitive elements; means for controlling the operation of the magnetising members and magnetically sensitive elements. and means for displaying or recording information. said information resulting from the processing of signals by said means for processing signals. in such a manner that information relating to physical or mechanical properties may be determined therefrom.
2. An apparatus for measuring parameters of moving ferromagnetic articles according to claim 1, wherein said means for processing signals and said means for controlling the operation of the magnetising members and magnetically sensitve elements jointly comprise a clock pulse generator, a current pulse generator or surge current generator. a plurality of peak detectors, a plurality of integrators. a plurality of reference sources of magnetic fields. a plurality of memory units. a unit for measuring the geometric mean of the output signals of the memory units and inverters operable for inverting the output signals of the magnetically sensitive elements.
3. An apparatus for me&suring parameters of mQving f=magmtic erticles a=rc&g to CLaim 1 ar 2, mprLgirg a swies mTwtion of a generator of current pulses, having connected to oneof its outputstwo magnetizing members disposed on two opposite sides of a moving article under inspection, and of a clock pulse generator having connected to the second output thereof the respectIve reset Inputs of two inteErators and the respective control Inputs of two peak detectors, two memory units having their respective control Inputs connectecl to the first output of the clock pulse generator and their respective outputs connected with the input of a unit for measuring the geometric mean of output signals,, having its out- put connected to a recorder, two circuits including each a series connection of a magnetically sensitive element and one of the two Deak detectors of which the reset input is connected to the other output of the generator of current pulses, two inverters having their respective Inputs connected to the outputs of the respective magnetically sensitive elements disposed to the two opposite sides of the moving article under inspectionj and two circuits each in cluding a series connection of an integrator having its first data input connected with the output of the res pective peak detector and its second data input connected with the output of the respective inverter, and a refe rence source of a magnetic field, arranged in the area of response of the respective magnetically sensitive element, c having its output connected to the data i.--:ut of the res- pective merory unit.
15.
4. An apparatus as claimed in any previous claim, wherein te pulserepetltion period of the clock pulse --enerator satis- fles a condition:
-' T p where 1 is the spacing between the pair of marnetizirp, members and the pair of magnetically sensitive elements, V is the speed of the motion of the article under inspection, and T -Js the pulse repetition rat-e of the clock pulse generator.
5. An apparatus for measuring parameters of moving ferroriagnetic articles, as claimed Inany preceding Claim, substantially as hereintofore described with reference to the accompanying drawings.
Published 1990 at The Patent Office, State House, 68171 High Holborn, London WC1R 4TP. Further copies maybe obtalnedfrom The Patent Oftioe.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE19883843100 DE3843100A1 (en) | 1988-12-21 | 1988-12-21 | DEVICE FOR MEASURING THE PARAMETERS OF MOVABLE FERROMAGNETIC PRODUCTS |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| GB8901041D0 GB8901041D0 (en) | 1989-03-15 |
| GB2227320A true GB2227320A (en) | 1990-07-25 |
Family
ID=6369757
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB8901041A Withdrawn GB2227320A (en) | 1988-12-21 | 1989-01-18 | Apparatus for measuring parameters of moving ferromagnetic articles |
Country Status (3)
| Country | Link |
|---|---|
| DE (1) | DE3843100A1 (en) |
| FR (1) | FR2642171B1 (en) |
| GB (1) | GB2227320A (en) |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB756596A (en) * | 1953-05-30 | 1956-09-05 | Tata Iron & Steel Company Ltd | Method of and means for magnetic testing |
| GB1512690A (en) * | 1974-09-28 | 1978-06-01 | Basf Ag | Magnetic remanence measurement |
| GB2031155A (en) * | 1978-09-08 | 1980-04-16 | British Steel Corp | Isotropic magnetising system |
Family Cites Families (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB1067764A (en) * | 1964-05-04 | 1967-05-03 | Assembly Products | Method and apparatus for determining hardness of ferromagnetic material |
| JPS50951B1 (en) * | 1969-11-21 | 1975-01-13 | ||
| DE3338667A1 (en) * | 1983-10-25 | 1985-05-09 | Institut Prikladnoj Fiziki Akademii Nauk Belorusskoj SSR, Minsk | Device for measuring the physico-mechanical parameters of moving ferromagnetic products |
| CH664632A5 (en) * | 1984-08-16 | 1988-03-15 | Landis & Gyr Ag | CIRCUIT ARRANGEMENT FOR COMPENSATING VARIATIONS OF THE TRANSMISSION FACTOR OF A MAGNETIC FIELD SENSOR. |
-
1988
- 1988-12-21 DE DE19883843100 patent/DE3843100A1/en not_active Withdrawn
-
1989
- 1989-01-18 GB GB8901041A patent/GB2227320A/en not_active Withdrawn
- 1989-01-20 FR FR8900690A patent/FR2642171B1/en not_active Expired - Fee Related
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB756596A (en) * | 1953-05-30 | 1956-09-05 | Tata Iron & Steel Company Ltd | Method of and means for magnetic testing |
| GB1512690A (en) * | 1974-09-28 | 1978-06-01 | Basf Ag | Magnetic remanence measurement |
| GB2031155A (en) * | 1978-09-08 | 1980-04-16 | British Steel Corp | Isotropic magnetising system |
Also Published As
| Publication number | Publication date |
|---|---|
| FR2642171A1 (en) | 1990-07-27 |
| GB8901041D0 (en) | 1989-03-15 |
| DE3843100A1 (en) | 1990-06-28 |
| FR2642171B1 (en) | 1991-04-26 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| WAP | Application withdrawn, taken to be withdrawn or refused ** after publication under section 16(1) |