CA1069200A - Apparatus for sensing moving particles or small moving objects - Google Patents
Apparatus for sensing moving particles or small moving objectsInfo
- Publication number
- CA1069200A CA1069200A CA257,217A CA257217A CA1069200A CA 1069200 A CA1069200 A CA 1069200A CA 257217 A CA257217 A CA 257217A CA 1069200 A CA1069200 A CA 1069200A
- Authority
- CA
- Canada
- Prior art keywords
- plate
- strips
- grain
- sensing
- objects
- 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
-
- A—HUMAN NECESSITIES
- A01—AGRICULTURE; FORESTRY; ANIMAL HUSBANDRY; HUNTING; TRAPPING; FISHING
- A01D—HARVESTING; MOWING
- A01D41/00—Combines, i.e. harvesters or mowers combined with threshing devices
- A01D41/12—Details of combines
- A01D41/127—Control or measuring arrangements specially adapted for combines
- A01D41/1271—Control or measuring arrangements specially adapted for combines for measuring crop flow
- A01D41/1272—Control or measuring arrangements specially adapted for combines for measuring crop flow for measuring grain flow
- A01D41/1273—Control or measuring arrangements specially adapted for combines for measuring crop flow for measuring grain flow for measuring grain loss
-
- 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
- G01F1/66—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 measuring frequency, phase shift or propagation time of electromagnetic or other waves, e.g. using ultrasonic flowmeters
- G01F1/666—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 measuring frequency, phase shift or propagation time of electromagnetic or other waves, e.g. using ultrasonic flowmeters by detecting noise and sounds generated by the flowing fluid
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N29/00—Investigating or analysing materials by the use of ultrasonic, sonic or infrasonic waves; Visualisation of the interior of objects by transmitting ultrasonic or sonic waves through the object
- G01N29/04—Analysing solids
- G01N29/045—Analysing solids by imparting shocks to the workpiece and detecting the vibrations or the acoustic waves caused by the shocks
- G01N29/046—Analysing solids by imparting shocks to the workpiece and detecting the vibrations or the acoustic waves caused by the shocks using the echo of particles imparting on a surface; using acoustic emission of particles
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N2291/00—Indexing codes associated with group G01N29/00
- G01N2291/02—Indexing codes associated with the analysed material
- G01N2291/024—Mixtures
- G01N2291/02408—Solids in gases, e.g. particle suspensions
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N2291/00—Indexing codes associated with group G01N29/00
- G01N2291/02—Indexing codes associated with the analysed material
- G01N2291/028—Material parameters
- G01N2291/02836—Flow rate, liquid level
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N2291/00—Indexing codes associated with group G01N29/00
- G01N2291/04—Wave modes and trajectories
- G01N2291/042—Wave modes
- G01N2291/0421—Longitudinal waves
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N2291/00—Indexing codes associated with group G01N29/00
- G01N2291/04—Wave modes and trajectories
- G01N2291/042—Wave modes
- G01N2291/0422—Shear waves, transverse waves, horizontally polarised waves
Landscapes
- Physics & Mathematics (AREA)
- Life Sciences & Earth Sciences (AREA)
- General Physics & Mathematics (AREA)
- General Health & Medical Sciences (AREA)
- Health & Medical Sciences (AREA)
- Chemical & Material Sciences (AREA)
- Analytical Chemistry (AREA)
- Biochemistry (AREA)
- Acoustics & Sound (AREA)
- Environmental Sciences (AREA)
- Immunology (AREA)
- Pathology (AREA)
- Electromagnetism (AREA)
- Fluid Mechanics (AREA)
- Measurement Of Mechanical Vibrations Or Ultrasonic Waves (AREA)
- Investigating Or Analyzing Materials By The Use Of Ultrasonic Waves (AREA)
Abstract
ABSTRACT OF THE DISCLOSURE
A detector for sensing the presence of grain in straw or chart discharged from a combine has an elongated flat target plate extending across the machine.
It is mounted on a relatively massive base through the intermediary of longitudinal resilient strips, which allow transverse bending. Transducers mounted on the reverse side of the plate provide an output from which sharp, grain impact signals can be filtered. The resilient strips are best arranged along nodes of a selected harmonic, preferably the second, of the transverse bending vibrations of the plate. The detector can be used generally for sensing small particles.
A detector for sensing the presence of grain in straw or chart discharged from a combine has an elongated flat target plate extending across the machine.
It is mounted on a relatively massive base through the intermediary of longitudinal resilient strips, which allow transverse bending. Transducers mounted on the reverse side of the plate provide an output from which sharp, grain impact signals can be filtered. The resilient strips are best arranged along nodes of a selected harmonic, preferably the second, of the transverse bending vibrations of the plate. The detector can be used generally for sensing small particles.
Description
~ = -~6g2~0 Tnis invention relates to apparatus for sensing or aetectiny small moving particles or small moving objects, and is particularly though not exclusively applicable to apparatus for sensing or detecting cereal grain. The invention may be used to sense the grain lost with the straw or chaf~
from a combine harvester.
The invention is concerned with particle detectors of the type having a target on which the particles impinge, and an acoustic transducer for detecting consequent vibrations of the target. An earlier example is described in the Specification of our British Patent No. 13~4882 in which the target is an elongated cylindrical drum, filled with liquid and with micro-phones at one or each end. This has give~ good results, but it does have a drawback in that its sensitivity varies across its width.
It would be better to have a sensor in the form of a flat strip of uniform sensitivity across its width, for then the whole area would give a useful response and sample a larger proportion of the straw stream for a given obstructlon; ~ ~ --It is an object of this invention to provide such a sensor.
According to the present invention there is provided apparatus for sensing moving particles or small moving objects comprising an elongated substantially flat plate one side of which is a target for said objects and which detectably vibrates in response to impacts by said objects, a base, relatively massive in relation to the plate, parallel regularly spaced resilient strips interposed between the base and the other side of the platle and extending longitudinally of the plate to , ;.
from a combine harvester.
The invention is concerned with particle detectors of the type having a target on which the particles impinge, and an acoustic transducer for detecting consequent vibrations of the target. An earlier example is described in the Specification of our British Patent No. 13~4882 in which the target is an elongated cylindrical drum, filled with liquid and with micro-phones at one or each end. This has give~ good results, but it does have a drawback in that its sensitivity varies across its width.
It would be better to have a sensor in the form of a flat strip of uniform sensitivity across its width, for then the whole area would give a useful response and sample a larger proportion of the straw stream for a given obstructlon; ~ ~ --It is an object of this invention to provide such a sensor.
According to the present invention there is provided apparatus for sensing moving particles or small moving objects comprising an elongated substantially flat plate one side of which is a target for said objects and which detectably vibrates in response to impacts by said objects, a base, relatively massive in relation to the plate, parallel regularly spaced resilient strips interposed between the base and the other side of the platle and extending longitudinally of the plate to , ;.
- 2 -~L~69ZOO
mount the latter on the base, tne spacing of the strips being sucn that they coincide with nodes of a selected harmonic of transverse bending vibrations of the plate, and transducer means mounted on said other side of the plate between resilient strips to respond to said vibrations.
Conveniently the second harmonic is selected, and then there are three resilient mounting stri~s with two transducers mounted between respective adjacent pairs of strips.
For reasons to be explained it is advantageous to mount the transducers with opposite polarities.
For a better understanding of the invention one constructional form will now be described, by way of example, with reference to the remaining figures of the accompanying drawings, in wnich;
Fig. 1 is a diagrammatic cross section of a prior art sensor;
Figure 2 is a diagrammatic side elevation of a combine harvester with two grain detector elements; and ~ ~
Figure 3 is a cross-section of a detector according , . . . .
2~ to the invention, showing a related response characteristic.
~ eferring to Fig. 1, showing a prior art sensor, it will be seen ~at for particles moving in the direction of the~
- arrow, those impinging on the cylinder over the central zone A
strike almost normally against the surface and therefore provlde firm impacts giving full sensitivity. Particles impinging to-wards the edge zones 13 only strike glanciny blows and do not produce such a good response.
Combine harvesters are well known and will not be described in detail. In Figure 2 the harvester has a driving
mount the latter on the base, tne spacing of the strips being sucn that they coincide with nodes of a selected harmonic of transverse bending vibrations of the plate, and transducer means mounted on said other side of the plate between resilient strips to respond to said vibrations.
Conveniently the second harmonic is selected, and then there are three resilient mounting stri~s with two transducers mounted between respective adjacent pairs of strips.
For reasons to be explained it is advantageous to mount the transducers with opposite polarities.
For a better understanding of the invention one constructional form will now be described, by way of example, with reference to the remaining figures of the accompanying drawings, in wnich;
Fig. 1 is a diagrammatic cross section of a prior art sensor;
Figure 2 is a diagrammatic side elevation of a combine harvester with two grain detector elements; and ~ ~
Figure 3 is a cross-section of a detector according , . . . .
2~ to the invention, showing a related response characteristic.
~ eferring to Fig. 1, showing a prior art sensor, it will be seen ~at for particles moving in the direction of the~
- arrow, those impinging on the cylinder over the central zone A
strike almost normally against the surface and therefore provlde firm impacts giving full sensitivity. Particles impinging to-wards the edge zones 13 only strike glanciny blows and do not produce such a good response.
Combine harvesters are well known and will not be described in detail. In Figure 2 the harvester has a driving
3 ~
,.. . . . . . . . . . . . . ... . . . . . .
- ~LC169200 position 1 at the front of the machine and conventional mechanism for cutting the grain and delivering it to the :
straw and chaff separators. There is a straw walker 2 arranged ~, ,~
-', :~ ~ 3a - -$
. ' , : . ' - ,- ~ . : . . ~ . : ' . .
~6~ZO(~
to discharge straw from beneath a hood 3 at the rear of the machine. Below the straw walker is a grain sieve system 4 designed to separate grain from the chaff and to discharge the chaff at a zone 5, also within the hood 3. Particle detecting elements 6 are positioned within the hood immediately below the output end of the straw walker 3 and immediately below the discharge end of the grain sieve 4. Each detector extends horizontally across the full width of the respective straw wal~er or grain sieve, so that a proportion or constant fraction of the grain that is lost from either of these devices will impinge on one of the target elements and produce an output signal.
The detectors are connected by cables 7 and 8 to a metering and display unit 9 positioned in front of the driving position:so as to be readily visible. ~he unit 9 may include counting or integrating devices to provide an output indication corresponding to the rate at which grain is being lost. Another output from the metering unit 9 is coupled to an automatic engine speed regulator 10 so that the speed of the combine harvester can be controlled in response to the sensed grain loss. `
The function of the detectors is to distinguish between grain and the straw and chaff. In the case of the walker sensor, for instance, the weight of the straw and the number of individual straws deflected by the sensor far outweighs the weight and numbers of grain. However . . .
the grains are denser and harder, so that individual grain impacts give impulses of shorter duration. The frequency spectrum of the short duration impulses contains a greater proportion of high frequenoies and these can be isolated
,.. . . . . . . . . . . . . ... . . . . . .
- ~LC169200 position 1 at the front of the machine and conventional mechanism for cutting the grain and delivering it to the :
straw and chaff separators. There is a straw walker 2 arranged ~, ,~
-', :~ ~ 3a - -$
. ' , : . ' - ,- ~ . : . . ~ . : ' . .
~6~ZO(~
to discharge straw from beneath a hood 3 at the rear of the machine. Below the straw walker is a grain sieve system 4 designed to separate grain from the chaff and to discharge the chaff at a zone 5, also within the hood 3. Particle detecting elements 6 are positioned within the hood immediately below the output end of the straw walker 3 and immediately below the discharge end of the grain sieve 4. Each detector extends horizontally across the full width of the respective straw wal~er or grain sieve, so that a proportion or constant fraction of the grain that is lost from either of these devices will impinge on one of the target elements and produce an output signal.
The detectors are connected by cables 7 and 8 to a metering and display unit 9 positioned in front of the driving position:so as to be readily visible. ~he unit 9 may include counting or integrating devices to provide an output indication corresponding to the rate at which grain is being lost. Another output from the metering unit 9 is coupled to an automatic engine speed regulator 10 so that the speed of the combine harvester can be controlled in response to the sensed grain loss. `
The function of the detectors is to distinguish between grain and the straw and chaff. In the case of the walker sensor, for instance, the weight of the straw and the number of individual straws deflected by the sensor far outweighs the weight and numbers of grain. However . . .
the grains are denser and harder, so that individual grain impacts give impulses of shorter duration. The frequency spectrum of the short duration impulses contains a greater proportion of high frequenoies and these can be isolated
- 4 ~
'.- , S~/GA
.... . ... . . . ... .. ... . ~ - .. ... . . .....
69;~00 by electrical filters. However, vibration resonances of the sensor also serve to emphasise certain frequencies.
Broadly, the larger the sensor, the lower the frequency of these mechanical vibration resonances. Thus for a large area sensor, further electrical filtering would have to be applied to reduce the effect of straw impact.
There is also the problem that, in practice, energy is absorbed by various modes of resonant vibrations and the ~ -energy available in the higher frequencies is reduced.
Mechanical damping of the sensor can reduce the predominance of low frequency vibrations, but it also tends to absorb vibrational energy before it can spread from the point of impact to the point at which the vibration is sensed. Therefore the sensitivity to impact is low in parts of the sensor remote from the transducer.
In order to achieve more uniform resonance, a high 'Q' factor of the resonant vibrations is required, for the higher that factor is the greater the number of cycles of vibration executed for a given factor of decay in amplitude. However, if there are a large number of impacts per unit time to be resolved, a low Q factor is desirable, namely one that is associated with a rapid decay in the resonance. Alternatively and preferably a high resonant frequency F can be adopted so that although Q may be high, ;
the ratio Q/~ is also high.
:: .
As~well as these requirements of a high 'Q' ! factor, a high Q/F ratio and a high resonant frequency F
to resolve adequately the impacts of grain from those of chaff and straw, a large area sensor is needed to respond j:~
, - 5 -SL/GA ~
.' . .. , - - . , ~ .
~6g2~0 to grain loss across the width of the combine. However, a high resonant frequency is not normally compatible with a large size sensor.
Referring now to Figure 3, there is shown a sensor or detector which, as wel:L as offering a good area facing the direction of straw or chaff flow, is mounted - in such a way that the high frequencies can be effectively isolated.
The detector comprises a wooden base in the form of a beam 11 which extends across the discharge stream and has on the side facing that s~ream an elongated aluminum plate 12 mounted by three hard rubber strips 13 extending long-itudinally of the detector and situated at the nodes of the second harrnonic of transverse vibrational bending of the plate 12. Centrally disposed between adjacent pairs of strips 13 and mounted on the underside of the plate 12 are transducers 14 of opposite polarities, and with leads 15 to an amplifier and further circuitry (not shown) but which is preferably of the kind described in our co-pending Canadlan Application l~o.
~ 20 257,634 filed 23 July 1976. As an example of dimensions, - the size of the cross-section of base 11 may be of the - order of 100 x 25 mm while the superimposed plate 12 may be of the order of 6 mrn thick. This mounting of the sensing plate 12 results in a very selective transmission of frequencies to the amplifier. The resilient mounting at the three nodal lines and the relatively massive wooden base wiil severely damp many other transverse modes, ;
i ~ - 6 -~, ''~,'.
~ i92~iD
especially odd harmonic modes, for example the fundamental, third fifth and so on. ~urthermore, with the transducers mounted with opposite polarities, similar and equal bending movements due to vibrations in the fundamental and odd harmonic modes cancel out. However, the opposite bending forces experienced by the transducers at the second harmonic mode (and at odd multiples thereof) are additive.
Longitudinal bending modes of vibration perpendicular to the plane of the sensor are completely cancelled.
~hese modes are of low frequency and large amplitude due to combine engine and suspension vibration. Their cancellation will greatly reduce the isolation required.
With such a detector of the size indicated, a high resonant frequency has been observed of approx.
12KHz. ~his shows a good 'Q' factor of the order of 20 to 50, whioh has been found to give a substantially uniform response over a length of about a metre. It permits the resolution of impulses with less than 5mS separation.
; A similar device but with just two strip supports has been compared with the sensor described, ànd this vibrates at about 5KHz. While it shows a slightly higher 'Q' factor,~
the impulse separation interval is now of the order of 10mS.`
It will be appreciated that the sensitivity of such a sensor is not uniform, varying across the width of the sensor as indicated by the graph at the top of Figuxe 3. The sensitivity reduces virtually to zero at the nodal lines. However, this is not a disadvantage in practice for between the nodes the response is reasonably uniform and there are no areas of exceptionally high sensitivity.
~ ' ~SL/GA
: ' . '' , 1~:3692~
Along its length the sensor is very uniformly sensitive.
The absence of liquid will allow easier mounting and use of such sensors, and low susceptibility to external vibration will allow a simple mounting, even to moving parts; for example to the shoe of a sieve or a walker.
It will be understood that these sensors can be employed in other applications where the detecting of hard particles is required and where particle flow rates are to be detected.
, " ` ': ;,'::
' . ': ;' '-SLtGA
,,":, ~ , : -'.''' ' ~:
'.- , S~/GA
.... . ... . . . ... .. ... . ~ - .. ... . . .....
69;~00 by electrical filters. However, vibration resonances of the sensor also serve to emphasise certain frequencies.
Broadly, the larger the sensor, the lower the frequency of these mechanical vibration resonances. Thus for a large area sensor, further electrical filtering would have to be applied to reduce the effect of straw impact.
There is also the problem that, in practice, energy is absorbed by various modes of resonant vibrations and the ~ -energy available in the higher frequencies is reduced.
Mechanical damping of the sensor can reduce the predominance of low frequency vibrations, but it also tends to absorb vibrational energy before it can spread from the point of impact to the point at which the vibration is sensed. Therefore the sensitivity to impact is low in parts of the sensor remote from the transducer.
In order to achieve more uniform resonance, a high 'Q' factor of the resonant vibrations is required, for the higher that factor is the greater the number of cycles of vibration executed for a given factor of decay in amplitude. However, if there are a large number of impacts per unit time to be resolved, a low Q factor is desirable, namely one that is associated with a rapid decay in the resonance. Alternatively and preferably a high resonant frequency F can be adopted so that although Q may be high, ;
the ratio Q/~ is also high.
:: .
As~well as these requirements of a high 'Q' ! factor, a high Q/F ratio and a high resonant frequency F
to resolve adequately the impacts of grain from those of chaff and straw, a large area sensor is needed to respond j:~
, - 5 -SL/GA ~
.' . .. , - - . , ~ .
~6g2~0 to grain loss across the width of the combine. However, a high resonant frequency is not normally compatible with a large size sensor.
Referring now to Figure 3, there is shown a sensor or detector which, as wel:L as offering a good area facing the direction of straw or chaff flow, is mounted - in such a way that the high frequencies can be effectively isolated.
The detector comprises a wooden base in the form of a beam 11 which extends across the discharge stream and has on the side facing that s~ream an elongated aluminum plate 12 mounted by three hard rubber strips 13 extending long-itudinally of the detector and situated at the nodes of the second harrnonic of transverse vibrational bending of the plate 12. Centrally disposed between adjacent pairs of strips 13 and mounted on the underside of the plate 12 are transducers 14 of opposite polarities, and with leads 15 to an amplifier and further circuitry (not shown) but which is preferably of the kind described in our co-pending Canadlan Application l~o.
~ 20 257,634 filed 23 July 1976. As an example of dimensions, - the size of the cross-section of base 11 may be of the - order of 100 x 25 mm while the superimposed plate 12 may be of the order of 6 mrn thick. This mounting of the sensing plate 12 results in a very selective transmission of frequencies to the amplifier. The resilient mounting at the three nodal lines and the relatively massive wooden base wiil severely damp many other transverse modes, ;
i ~ - 6 -~, ''~,'.
~ i92~iD
especially odd harmonic modes, for example the fundamental, third fifth and so on. ~urthermore, with the transducers mounted with opposite polarities, similar and equal bending movements due to vibrations in the fundamental and odd harmonic modes cancel out. However, the opposite bending forces experienced by the transducers at the second harmonic mode (and at odd multiples thereof) are additive.
Longitudinal bending modes of vibration perpendicular to the plane of the sensor are completely cancelled.
~hese modes are of low frequency and large amplitude due to combine engine and suspension vibration. Their cancellation will greatly reduce the isolation required.
With such a detector of the size indicated, a high resonant frequency has been observed of approx.
12KHz. ~his shows a good 'Q' factor of the order of 20 to 50, whioh has been found to give a substantially uniform response over a length of about a metre. It permits the resolution of impulses with less than 5mS separation.
; A similar device but with just two strip supports has been compared with the sensor described, ànd this vibrates at about 5KHz. While it shows a slightly higher 'Q' factor,~
the impulse separation interval is now of the order of 10mS.`
It will be appreciated that the sensitivity of such a sensor is not uniform, varying across the width of the sensor as indicated by the graph at the top of Figuxe 3. The sensitivity reduces virtually to zero at the nodal lines. However, this is not a disadvantage in practice for between the nodes the response is reasonably uniform and there are no areas of exceptionally high sensitivity.
~ ' ~SL/GA
: ' . '' , 1~:3692~
Along its length the sensor is very uniformly sensitive.
The absence of liquid will allow easier mounting and use of such sensors, and low susceptibility to external vibration will allow a simple mounting, even to moving parts; for example to the shoe of a sieve or a walker.
It will be understood that these sensors can be employed in other applications where the detecting of hard particles is required and where particle flow rates are to be detected.
, " ` ': ;,'::
' . ': ;' '-SLtGA
,,":, ~ , : -'.''' ' ~:
Claims (4)
1. Apparatus for sensing moving particles or small moving objects comprising an elongated substantially flat plate one side of which is a target for said objects and which detectably vibrates in response to impacts by said objects, a base, relatively massive in relation to the plate, parallel regularly spaced resilient strips interposed between the base and the other side of the plate and extending longitudinally of the plate to mount the latter on the base, the spacing of the strips being such that they coincide with nodes of a selected harmonic of transverse bending vibrations of the plate, and transducer means mounted on said other side of the plate between resilient strips to respond to said vibrations.
2. Apparatus as claimed in claim 1, wherein the selected harmonic is the second, there being three said resilient strips with two transducers mounted between respective adjacent pairs of strips.
3. Apparatus as claimed in claim 2, wherein the transducers are mounted with opposite polarities.
4. A combine harvester equipped with apparatus as claimed in claim 1, 2 or 3 and arranged for detecting waste grain.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB3055175A GB1552794A (en) | 1975-07-22 | 1975-07-22 | Apparatus for sensing moving particles or small moving objjects |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1069200A true CA1069200A (en) | 1980-01-01 |
Family
ID=10309416
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA257,217A Expired CA1069200A (en) | 1975-07-22 | 1976-07-19 | Apparatus for sensing moving particles or small moving objects |
Country Status (4)
| Country | Link |
|---|---|
| AU (1) | AU502601B2 (en) |
| CA (1) | CA1069200A (en) |
| DE (1) | DE2632507A1 (en) |
| GB (1) | GB1552794A (en) |
Families Citing this family (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4517792A (en) * | 1982-05-07 | 1985-05-21 | Deere & Company | Grain loss monitor sensor mounting arrangement for a combine |
| DE3731080A1 (en) * | 1987-09-16 | 1989-03-30 | Claas Ohg | LOSS GRAIN SENSOR FOR HARVESTING MACHINES |
| US5046362A (en) * | 1988-04-26 | 1991-09-10 | Ford New Holland, Inc. | Grain loss monitors for harvesting machines |
| EP0339142B1 (en) * | 1988-04-26 | 1992-09-02 | Ford New Holland N.V. | Impact detectors |
| DE3884602T2 (en) * | 1988-04-26 | 1994-02-17 | Ford New Holland Inc | Grain loss monitors for mowers. |
| DE3900450A1 (en) * | 1989-01-10 | 1990-07-12 | Hergeth Hubert | System for separating stones out of a fibre stream |
| DE4138533A1 (en) * | 1991-11-23 | 1993-05-27 | Kloeckner Humboldt Deutz Ag | Granular flowmeter for harvester thresher - detects change in physical field e.g. electric field or light beam, caused by flow of grain through outlet path |
| DE4138531A1 (en) * | 1991-11-23 | 1993-05-27 | Kloeckner Humboldt Deutz Ag | Granular flowmeter for harvester thresher grain elevator - has measurement position at end of rocker in which grain flow affects electric or electromagnetic field |
| DE19912372C1 (en) | 1999-03-19 | 2000-11-09 | Case Harvesting Sys Gmbh | Device for measuring the grain fraction in a return of a combine harvester |
| CN109489747B (en) * | 2018-12-24 | 2020-03-20 | 合肥工业大学 | Electromagnetic flowmeter signal processing method based on harmonic analysis |
-
1975
- 1975-07-22 GB GB3055175A patent/GB1552794A/en not_active Expired
-
1976
- 1976-07-19 CA CA257,217A patent/CA1069200A/en not_active Expired
- 1976-07-20 DE DE19762632507 patent/DE2632507A1/en not_active Withdrawn
- 1976-07-22 AU AU16147/76A patent/AU502601B2/en not_active Expired
Also Published As
| Publication number | Publication date |
|---|---|
| GB1552794A (en) | 1979-09-19 |
| AU502601B2 (en) | 1979-08-02 |
| DE2632507A1 (en) | 1977-04-21 |
| AU1614776A (en) | 1978-01-26 |
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