U.S. patent application number 14/886436 was filed with the patent office on 2018-04-12 for probe and method for obtaining rheological property value.
This patent application is currently assigned to I.B.B. RHEOLOGIE INC.. The applicant listed for this patent is Denis Beaupre, Frederic Chapdelaine, Jerome Chapdelaine. Invention is credited to Denis Beaupre, Frederic Chapdelaine, Jerome Chapdelaine.
Application Number | 20180100791 14/886436 |
Document ID | / |
Family ID | 58526782 |
Filed Date | 2018-04-12 |
United States Patent
Application |
20180100791 |
Kind Code |
A9 |
Beaupre; Denis ; et
al. |
April 12, 2018 |
Probe and Method for Obtaining Rheological Property Value
Abstract
The probe can include a base and a resistance member extending
from the base and onto which a resistance pressure is imparted by a
rheological substance when the resistance member is submerged and
moved therein. Rheological properties can be obtained using values
indicative of the resistance pressure both in a low speed range and
in a high speed range.
Inventors: |
Beaupre; Denis; (Abu Dhabi,
AE) ; Chapdelaine; Jerome; (Quebec, CA) ;
Chapdelaine; Frederic; (Saint-Nicolas, CA) |
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Applicant: |
Name |
City |
State |
Country |
Type |
Beaupre; Denis
Chapdelaine; Jerome
Chapdelaine; Frederic |
Abu Dhabi
Quebec
Saint-Nicolas |
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AE
CA
CA |
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|
Assignee: |
I.B.B. RHEOLOGIE INC.
|
Prior
Publication: |
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Document Identifier |
Publication Date |
|
US 20170108421 A1 |
April 20, 2017 |
|
|
Family ID: |
58526782 |
Appl. No.: |
14/886436 |
Filed: |
October 19, 2015 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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13500643 |
Apr 6, 2012 |
9199391 |
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PCT/IB10/54542 |
Oct 7, 2010 |
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14886436 |
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61249321 |
Oct 7, 2009 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
G01N 11/14 20130101;
G01N 2011/0046 20130101; G01N 11/10 20130101 |
International
Class: |
G01N 11/14 20060101
G01N011/14 |
Claims
1. A rheological probe unit for use in a cylindrical container
rotatable about its axis and containing a substance having
rheological properties, the rheological probe unit comprising: a
base mountable in a wall of the cylindrical container; a resistance
member extending from the base in a radial orientation when the
base is mounted to the cylindrical container, and onto which a
normal resistance pressure is imparted by the rheological substance
when the resistance member is submerged and moved therein by the
rotation of the cylindrical container; a force sensor adapted to
provide force values indicative of the resistance pressure at given
points in time; a speed sensor adapted to provide speed values
indicative of the speed at which the resistance member is moved in
the substance at given points in time, in both a low speed range
and a high speed range; a power source; a rheological value
calculator powered by said power source and adapted to obtain a
calculated value indicative of at least one of said rheological
properties of the substance using at least one of both; a force
value and speed value in the low speed range corresponding to a
given point in time; and a force value and speed value in the high
speed range corresponding to another given point in time; and an
emitter.
2. The rheological probe unit of claim 1, wherein the resistance
member has an elongated stem having a deformation portion which
deforms in reaction to the resistance pressure, and the force
sensor includes a load cell positioned on the deformation
portion.
3. The rheological probe unit of claim 1 wherein the emitter is
connected to the rheological value calculator to emit data
corresponding to said calculated value.
4. The rheological probe unit of claim 1 wherein the speed sensor
includes a position sensor providing a position value indicative of
the position of the probe around the axis, and a speed calculator
adapted to calculate a speed value based on the variation of the
position value in time.
5. The rheological probe unit of claim 4 wherein the axis is
inclined relative to a vertical orientation, wherein the position
sensor includes an accelerometer oriented toward said axis.
6. The rheological probe unit of claim 1 further comprising a
memory module for storing a distance value corresponding to the
average distance travelled by the rheological probe during each
revolution, and a timer obtaining a time value corresponding to
time elapsed between successive rapid increases in the force value
which correspond to successive entries of the resistance member
into the substance; wherein the speed sensor obtains the speed
values by dividing the distance value by the time value.
7. The rheological probe unit of claim 1 further comprising a
temperature sensor adapted to provide a temperature value
indicative of the temperature of the substance, wherein said
emitter is connected to the temperature sensor to emit data
corresponding to the temperature value.
8. The rheological probe unit of claim 1 wherein the container is a
drum of a cement truck, the rheological value calculator has a
function to calculate a slope between the at least one force value
and speed value in the low speed range and the at least one force
value and speed value in the high speed range, the slope being
indicative of a viscosity rheological property, and a function to
determine a zero speed pressure based on the slope, the zero speed
pressure being indicative of a yield rheological property.
9-16. (canceled)
17. A probe for determining at least one rheological property of a
fluid contained in a recipient, the probe comprising: an inner
member holding a load cell; an outer member adapted to be placed in
contact with said fluid, said outer member being submittable to a
pressure applied by the fluid and being adapted to transfer a force
resulting from said pressure to the inner member and thereby deform
the load cell, the load cell thence providing an indication of a
value of said deformation; a base connected to the inner member,
said load cell being prevented from being in contact with said
fluid by said outer member and said base; at least one position
sensor to provide an indication of a position of the probe; an
electronic module in electronic communication with the load cell
and the at least one position sensor, the electronic module having
a processing unit to determine a speed value of the probe based on
said indication of a position and to determine the at least one
rheological property of the fluid based on the speed value of the
probe and the value of the deformation obtained from the load cell;
wherein said at least one rheological property of the fluid is
determined when the probe is displaced in the fluid in the
recipient and without having to remove a sample of fluid from the
recipient to analyze it externally.
18. The probe as claimed in claim 17, wherein said probe is adapted
to move with a rotary mixer, the base being adapted to be mounted
to a wall of the mixer, the rotary mixer having a non-vertical axis
of rotation, said outer member being in periodic contact with said
fluid during rotation of said rotating mixer, wherein said at least
one rheological property of the fluid is determined when the probe
is in operation in the rotating mixer.
19. The probe as claimed in claim 17, wherein said processing unit
uses both said indication of a position and said value of the force
to determine said speed value of the probe.
20. The probe as claimed in any one of claim 17, wherein said at
least one position sensor has an accelerometer.
21. The probe of claim 20, wherein the processing unit determines
the speed based on a gravitational acceleration and the centripetal
acceleration of the probe.
22. The probe of claim 17, wherein the at least one rheological
property is one of viscosity and yield.
23. A method for determining at least one rheological property of a
fluid contained in a recipient, the method comprising: providing an
indication of a position value of the probe using at least one
position sensor; sensing a deformation of an outer member of a
probe resulting from a force applied by the fluid on the probe and
providing an indication of a value of said deformation; determining
a value of the force applied to the probe when in contact with said
fluid in said recipient using said value of said deformation;
determining a speed value of the probe using the determined
position value; and determining the at least one rheological
property of the fluid based on said speed value of the probe and
the value of the force applied on the probe; wherein said at least
one rheological property of the fluid is determined when the probe
is displaced in the fluid in the recipient and without having to
remove a sample of fluid from the recipient to analyze it
externally.
24. The rheological probe unit of claim 8 wherein the rheological
value calculator has a function to determine a slump rheological
property based on the yield rheological property using at least one
of a calibration of the rheological probe unit using different
compositions of fluid, a lookup table and a curve fitting equation.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of pending application
Ser. No. 13/500,643, filed Apr. 6, 2012, which is a national stage
application of PCT/IB10/54542, filed Oct. 7, 2010, which claimed
priority of U.S. Provisional application no. 61/249,321 filed Oct.
7, 2009, the disclosures of each of which are incorporated by
reference herein.
BACKGROUND OF THE INVENTION
[0002] Rheology is the study of the flow of matter. This
application more specifically addresses the flow of soft solids
which exhibit fluid-like behaviors. Many applications can benefit
from or even require the measurement of rheological properties of
substances, particularly in cases where such properties change over
time.
[0003] Concrete is a good example, for once mixed, concrete is
typically continuously mixed in a mixer, which are sometimes
mounted on trucks, to extend its life prior to solidification.
However, even though mixers extend the life of mixed concrete, it
does not make it last indefinitely, and the rheological properties
of concrete in the mixer such as viscosity and yield can vary over
time. For this reason, a common testing method referred to as the
slump test is commonly used to monitor the "workability" of the
concrete prior to application. The slump test involves removing
concrete from the mixer, placing it in a truncated cone of a given
height, removing the cone, waiting for the concrete to stabilize,
and measuring the distance the concrete has slumped down.
[0004] In the food industry to give another example, some
rheological properties can vary during cooking or other chemical
reactions, and monitoring rheological properties can provide
indicia that a given step in the process has been completed.
[0005] There are modern methods of obtaining rheological
properties, but each had particular limitations. There remained
room for improvement
SUMMARY OF THE INVENTION
[0006] Considering one aspect, providing a stand-alone instrument
which can be referred to as a probe, which has both means of
monitoring the resistance to movement or pressure exerted thereon
by the substance to characterize, and means of monitoring the
movement speed of the probe relative the substance, from which
rheological properties such as yield and viscosity can be
calculated, can provide a significant advantage, especially when
used on a wall of a revolving container for instance, where
external communication with other units poses challenges.
[0007] Henceforth, in accordance with one aspect, there is provided
a rheological probe unit for use in a cylindrical container
rotatable about its axis and containing a substance having
rheological properties, the rheological probe unit comprising: a
base mountable in a wall of the cylindrical container; a resistance
member extending from the base in a radial orientation when the
base is mounted to the cylindrical container, and onto which a
resistance pressure is imparted by the rheological substance when
the resistance member is submerged and moved therein by the
rotation of the cylindrical container; a force sensor adapted to
provide force values indicative of the resistance pressure at given
points in time; a speed sensor adapted to provide speed values
indicative of the speed at which the resistance member is moved in
the substance at given points in time, in both a low speed range
and a high speed range; a power source; and an emitter.
[0008] Considering another aspect, the measurement of the
resistance to movement exerted by the substance to characterize
posed particular challenges which remained to be addressed.
Henceforth, in accordance with another aspect, there is provided :
a rheological probe for use in obtaining at least one value
indicative of a rheological property of a substance in which the
rheological probe is to be immersed and relative to which the
rheological probe is to be transversally moved, the rheological
probe unit comprising : a base; an inner member fixedly connected
to the base and extending away therefrom, the inner member having
in succession base portion proximate the base, a deformation
portion located away from the base, and a tip; a shell member
covering the inner member from the tip and downwardly along the
deformation portion and base portion, the shell member being
pivotable about an axis extending across the base portion when
subjected to a resistance pressure imparted by the relative
movement in the rheological substance, and being connected to the
tip to transfer a force resulting from the resistance pressure and
thereby elastically deform the deformation portion; and a
deformation sensor mounted to the deformation portion for providing
a value indicative of the resistance pressure.
[0009] Also, in accordance with still another aspect, there is
provided a probe for determining at least one rheological property
of a fluid contained in a recipient, the probe comprising: an inner
member holding a load cell; an outer member adapted to be placed in
contact with said fluid, said outer member being submittable to a
pressure applied by the fluid and being adapted to transfer a force
resulting from said pressure to the inner member and thereby deform
the load cell, the load cell thence providing an indication of a
value of said deformation; a base connected to the inner member,
said load cell being prevented from being in contact with said
fluid by said outer member and said base; at least one position
sensor to provide an indication of a position of the probe; an
electronic module in electronic communication with the load cell
and the at least one position sensor, the electronic module having
a processing unit to determine a speed value of the probe based on
said indication of a position and to determine the at least one
rheological property of the fluid based on the speed value of the
probe and the value of the deformation obtained from the load cell;
wherein said at least one rheological property of the fluid is
determined when the probe is displaced in the fluid in the
recipient and without having to remove a sample of fluid from the
recipient to analyze it externally.
[0010] In accordance with another aspect, there is provided a
method for determining at least one rheological property of a fluid
contained in a recipient, the method comprising: providing an
indication of a position value of the probe using at least one
position sensor; sensing a deformation of an outer member of a
probe resulting from a force applied by the fluid on the probe and
providing an indication of a value of said deformation; determining
a value of the force applied to the probe when in contact with said
fluid in said recipient using said value of said deformation;
determining a speed value of the probe using the determined
position value; and determining the at least one rheological
property of the fluid based on said speed value of the probe and
the value of the force applied on the probe; wherein said at least
one rheological property of the fluid is determined when the probe
is displaced in the fluid in the recipient and without having to
remove a sample of fluid from the recipient to analyze it
externally.
[0011] In accordance with still another aspect, there is provided a
probe adapted to move with a mixer for determining at least one
rheological property of a fluid, the probe comprising: an outer
member being deformable when submitted to a force applied by the
fluid, the outer member comprising: an inner member connected to
the base for holding a load cell in condition to be deformed; a
load cell having a first end connected to the inner member and a
second end connected to the outer member for sensing the force
applied by the fluid on the outer member and being deformed by the
force and determining a value of the force, the load cell being
deformed proportionally to the deformation of the outer member; and
a base connected to the outer member and the inner member, the base
being adapted to be mounted on an interior wall of the mixer, the
base comprising: an electronic module in electronic communication
with the load cell, the electronic module having at least one
position sensor placed on an axis parallel to a mixer radius vector
to determine a position value of the probe and a processing unit to
determine a speed value of the probe, the processing unit
determining the at least one rheological property of the fluid
based on the speed value of the probe and the value of the force
obtained from the load cell when the probe is in operation in the
mixer without having to remove a sample of fluid from the mixer and
analyze it externally, the processing unit synchronizing the force
applied by the fluid on the outer member with the position value to
determine the speed value.
[0012] In accordance with a further aspect, there is provided a
probe adapted to move with a mixer for determining at least one
rheological property of a fluid, the probe comprising: an outer
member being deformable when submitted to a force applied by the
fluid, the outer member comprising: an inner member connected to
the base for holding a load cell in condition to be deformed; a
load cell having a first end connected to the inner member and a
second end connected to the outer member for sensing the force
applied by the fluid on the outer member and being deformed by the
force and determining a value of the force, the load cell being
deformed proportionally to the deformation of the outer member; and
a base connected to the outer member and the inner member, the base
being adapted to be mounted on an interior wall of the mixer, the
base comprising: an electronic module in electronic communication
with the load cell, the electronic module having at least one
accelerometer to determine a position value of the probe and a
processing unit to determine a speed value of the probe, the
processing unit determining the at least one rheological property
of the fluid based on the speed value of the probe and the value of
the force obtained from the load cell when the probe is in
operation in the mixer without having to remove a sample of fluid
from the mixer and analyze it externally.
[0013] In accordance with another aspect, there is provided a
method for determining at least one rheological property of a fluid
in a mixer, the method comprising: determining a position value of
the probe using at one accelerometer; detecting a deformation of an
outer member of a probe resulting from a force applied by the fluid
on the probe; determining a value of the force applied to the probe
when in operation in the mixer; determining a speed value of the
probe moving with the mixer using the determined position value;
and determining the at least one rheological property of the fluid
based on a speed values of the probe and the value of the force
applied on the probe when in operation in the mixer without having
to remove a sample of fluid from the mixer and analyze it
externally.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] Further features and advantages of the present invention
will become apparent from the following description in conjunction
with the appended drawings, in which:
[0015] FIG. 1 is a schematical side view of a mixing truck;
[0016] FIG. 2 is a schematical cross-section view of the mixer of
FIG. 1 taken along cross-section lines 2-2 showing an example of a
probe;
[0017] FIG. 3 is a longitudinal cross-sectional view of the probe
of FIG. 2;
[0018] FIG. 4 is a block diagram representation of the probe of
FIG. 2;
[0019] FIG. 5 is a schematic diagram of vectors used to determine
speed values of a probe in accordance with an embodiment;
[0020] FIG. 6A and 6B are graphical representations of calibration
data ;
[0021] FIG. 7 is a graphical representation of speed versus
pressure values obtained during operation of a probe in accordance
with FIG. 2;
[0022] FIG. 8 is a flow chart of a method in accordance with an
embodiment;
[0023] FIG. 9 is a side view, partly sectioned, of another example
of a probe;
[0024] FIG. 10 is a block diagram representation of another example
of a probe.
[0025] It will be noted that throughout the appended drawings, like
features are identified by like reference numerals.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0026] Reference is made to FIG. 1, which is provided to provide
context of one example of a possible application of a probe, that
is to obtain rheological properties of concrete inside the mixer 2
of a mixing truck. FIG. 1 shows a side view of a truck, with probe
10 schematically shown in the mixer 2 to obtain indications of
rheological properties. It can further obtain indications of mixer
speed and direction, fluid flow properties, fluid temperature for
instance, as will be detailed below. Because there is a challenge
in bringing a wired connection inside a rotary container, the probe
can transmit data to a receiver 3 via a wireless connection and be
self-powered. In a mixing truck, the rotation axis 6 of the mixer
is strongly inclined relative to the vertical.
[0027] Following this example, reference will be made to concrete
as being the substance to rheologically characterize; but it is
understood that the probe can be used with another container or
recipient than a mixer 2, rotary or not, which may contain other
substances exhibiting rheological properties such as fluids for the
food processing industry, the paint industry, the oil industry,
etc. Similarly mixers are not necessarily provided on trucks and
other types of mixers can be used. For example, the mixer can be an
industrial mixer, a blending system including high shear mixers,
in-line mixers, or agitators.
[0028] Reference is now made to FIG. 2, showing an example of a
probe 10. In this example, the probe 10 has a base 11, which is
affixed to the interior wall of the mixer 2. In the case of a
mixing truck, for instance, the probe 10 can be mounted in the
inspection door of the mixer 2 and the base can have an openable
bottom exposed outside the container for operations such as
maintenance. During use, the probe 10 rotates with the mixer 2 in
the rotating direction shown by arrows 5, or in the opposite
direction, depending of whether the mixer is mixing or emptying the
load, for instance. In both cases, the concrete remains toward the
bottom of the container due to the action of gravity and its
limited viscosity. The probe 10 is thus immersed into the concrete
at each revolution and travels therein. The concrete exerts a
resistance pressure shown schematically with arrows opposing the
movement of the probe 10. The probe 10 can directly measure
parameters such as the position of the probe, the force (or
resistance pressure exerted by the substance on the probe), the
temperature, etc. The probe 10 can subsequently use these
parameters to determine the speed, and thence use speed and force
values for instance to obtain an indication of properties of the
fluid such as the viscosity, the yield, the cohesion, etc. The
probe 10 can be made of any suitable material given the potentially
harsh environment.
[0029] In another embodiment, for example, the recipient can be
fixed and a probe can be moved manually, be provided on rails or
have other movement means over the recipient where the movement
means can be used to displace the probe at speeds which can
optionally be controlled.
[0030] Reference is now made to FIG. 3, which is a longitudinal
cross-sectional view of an example of a probe 10. The base 11
includes plates that can be adapted to be mounted to the wall of
the mixer 2, from the inside or the outside of the mixer, for
example using a hole perforated in the plate(s) and/or the mixer
wall.
[0031] The base 11 extends perpendicularly into the mixer 2 and
provides a hollow cavity 12 that can contain and protect an
electronic module 18, a power supply 19, and a transmitter 20 to
transmit data from the probe 10 to the receiver 3.
[0032] The electronic module 18 can be powered with replaceable or
rechargeable batteries for instance. In one embodiment, the
electronic module 18 can use various algorithms to reduce its power
requirements, and thus maintenance, such as turning off the radio
transmitter between transmissions, reducing its processing speed
when the mixer 2 does not rotate, etc. In another embodiment, the
batteries can be rechargeable and combined with one or more other
power sources such as solar panels, or inductive loops to further
reduce maintenance.
[0033] The probe 10 comprises an inner member 15, which is
connected to the base 11 and extends into the mixer 2. The inner
member 15 can be connected with the base using bolts or screws. The
inner member 15 can also be attached to the base 11 and maintained
in place with a seal 17.
[0034] The probe 10 comprises an outer member 13 which received the
resistance pressure from the substance. The outer member 13
comprises a hollow interior that allows the outer member 13 to
cover a load cell 14 and the inner member 15 of the base 11. The
outer member 13 is affixed to the base 11 with a pivot hinge 16.
The pivot hinge 16 maintains in place the outer member 13 with the
base 11 and allows the top part of the outer member 13 to slightly
move from left to right when the probe 10 is in operation in the
mixer 2. The movement of the outer member due to the pressure
exerted by the substance is transmitted to a deformation portion of
the inner member via a connection 44 (in this case an abutment
connection by abutment against the end of a bolt). The deformation
of the deformation portion 43 (in this case a metal plate) will be
sensed by the load cell 14 applied thereon, which can include one
or more strain gauges 42 for instance. A cap 45 is added at the end
of the outer member 13.
[0035] In one embodiment the outer member 13, the inner member 15
and the base 11 can be cylindrical. However, it is understood that
the outer member 13, and the base 11 can alternately have a
rectangular, a hexagonal, an ovoid shape, or any other shape. It
will be understood that the shape of these members which are in
contact with the mixture will affect the resistance of the probe 10
into the mixture.
[0036] In another embodiment, the inner member 15 can have a
rectangular, a hexagonal, an ovoid shape, or any other shape. It is
understood that the shape of the inner member will typically not
affect the operation of the probe.
[0037] The height of the resistance member, or more particularly
the outer shell in the above embodiment, can be selected as a
function of the properties of the substance to characterize.
Typically, soft solids reach a relative uniformity within a
characteristics scale which is in function of the largest
aggregates expectable in the substance. In the case of concrete for
instance, the characteristic scale is in the order of the
decimeter. Henceforth, the length or height of the resistance
member was selected to be within this order of magnitude, whereas
in an alternate embodiment for analysis of another substance having
a different characteristic scale, the length or height of the
resistance member can be adapted as a function of the
characteristic scale.
[0038] In the particular embodiment depicted, for the sake of
providing a truly full description, the probe can have a total
height of 40 cm (or 4 dm) for instance, in which case the outer
member can be 30 cm (or 3 dm) with a radius of 3.5 cm and the base
11 have an external radius of 4.5 cm for the purpose of giving a
full example. One feature which affects the amount pressure applied
to the outer member or shell is the surface area thereof.
Henceforth, for example, in an alternate embodiment where the
resistance member is wider, it can be selected to be shorter for
instance. When in use into the mixer 2, the base can be affixed
with together with a plate having of about 6 cm to the interior
wall of the mixer 2.
[0039] Reference is now made to FIG. 4, which is a schematic
diagram of an example of an electronic module 18 of a probe 10. In
this example, the electronic module 18 comprises an electrical
amplifier 61. The electrical variation of the strain gauge 42 is of
the order of a few millivolts and can thus require amplification by
the amplifier 61 before it can be used. The electrical amplifier 61
amplifies the electrical variation detected by strain gauge 42. The
electrical variation is then processed by the processing unit 62 to
obtain an indication of the pressure or force that was initially
applied by the fluid on the outer member 13. The processing unit 62
comprises instructions 63 of an algorithm. The instructions are
executed by the processing unit 62 to determine rheological
properties of the fluid. The processing unit 62 comprises software
and hardware parts to execute different algorithms to process
parameters measured by the probe 10.
[0040] The electronic module 18 may comprise a plurality of sensors
such as position sensors and temperature sensors. FIG. 4 shows a
position sensor 65 and a temperature sensor 64. The probe can have
memory such as a low speed point memory 67, a high speed point
memory 68 for storing measurements made by the plurality of sensors
of the probe 10.
[0041] The temperature sensor 64 measures the temperature inside
the probe 10. When the probe 10 is moving through the fluid, after
a stabilization delay, the temperature inside the probe 10
stabilizes to the fluid temperature. Hence, the temperature sensor
64 measures the fluid temperature. The probe 10 may use a Negative
Temperature Coefficient (NTC) resistor, which is also called a
thermistor. In another embodiment, other types of sensors can be
used are such as Resistance Temperature Detectors (RTDs),
semiconductors temperature sensors, etc.
[0042] The fluid temperature can be used as an information for
quality production control at a batching plant. For example, ice
can be added to maintain concrete in a concrete mixer truck
embodiment at a certain temperature. In this case, the temperature
sensor 64 is used as a feedback for the concrete temperature. The
temperature sensor can continuously measure and provide the
concrete temperature to determine the amount of ice to be added to
the concrete mixture.
[0043] The position sensor 65 can include a
micro-electro-mechanical system (MEMS) accelerometer for instance.
The accelerometer can be placed with is axis oriented toward the
axis of the mixer for instance and henceforth be affected by
centripetal acceleration and earth gravity acceleration to obtain
signal indicative of angular position. In this example, the
processing unit 62 combines the angular position readings with a
chronometer or timer to determine the probe rotation speed. The
processing unit 62 synchronizes the load cell reading with an
angular position sensor to systematically interpret measurements
from the probe 10, when the probe 10 is in operation and at the
bottommost point of its rotation into the mixture of the mixer
2.
[0044] Taking the measurements at the bottommost point of the
rotation of the mixer 2 ensures that the probe is located in the
mixture when acquiring the data. Using the accelerometers can allow
to determine the bottommost point.
[0045] Alternatively, the processing unit 62 can determine that the
probe 10 is in the mixture by continuously measuring the force
applied on the outer member 13. When the force increases
substantially, it means that the probe 10 is located in the fluid
and when the force decreases substantially, it means that the probe
is exiting the mixture. Thus, it can then be easier to remove a
noise component from the force signal as the noise would be
somewhat constant. This can also allow the determination of the
level of the fluid and thus by calculation, the amount of fluid in
the mixer.
[0046] Interestingly, a rough rotation speed can be estimated
without a position sensor simply by timing the delay between two
subsequent substantial increases or decreases in force, which gives
an indication of the time it takes for the drum to make a complete
revolution. If the information concerning the path of the probe is
available (typically linked to the diameter of the truck), the
length of the path can be divided by the time to give a rough
average speed approximation. Such processing by the processing unit
can thus constitute a speed sensor which can replace computation of
position data if desired.
[0047] Also, obtaining the information of the position at which the
probe enters and exits the substance by detection for instance of
sudden increase and sudden decrease in force value, can allow,
given the geometry of the container is available, to calculate a
value indicative of the volume of the substance in the
container.
[0048] Similarly, the determination of the presence of the probe 10
in the mixture can be made, for example, with the temperature
detected by the temperature sensor. When the temperature increases
substantially, the probe 10 is determined to be in the mixture and
when the temperature decreases substantially, the probe 10 is
determined to have exited the fluid or vice-versa, depending on the
qualities of the fluid being mixed.
[0049] By using the force value or the temperature value, the
processing unit 62 is able to determine if the probe is in the
fluid without knowing the amount of mixture in the mixer 2 and the
determination is therefore independent of the amount of mixture in
the mixer 2.
[0050] Alternately, if using a position sensor, the identification
of the position of entry of the probe and the position of exit can
be correlated to a volume of concrete in the mixer.
[0051] In one embodiment, any sensor that is able to produce a
signal indicative of a position reference for the probe 10 can be
used, such as an accelerometer, an inductive non-contact position
sensor, a string potentiometer, a linear variable differential
transformer, a potentiometer, a capacitive transducer, an
eddy-current sensor, a Hall effect sensor, a grating sensor, a
rotary encoder, a seismic displacement pick-up module, a
piezo-electric transducer, a photodiode array, etc.
[0052] Then the processing unit 62 can use an internal chronometer
to measure the time elapsed between each known position encounter.
The speed can be determined, and the absolute position of the mixer
2 at any given time can be interpolated.
[0053] In another embodiment, a magnetic sensor can be used as
reference. In this case, a magnet (or many magnets) is affixed to
the truck frame at a known position. A magnetic sensor in the probe
10 detects when the probe 10 moves near the magnet. In an alternate
embodiment a reflective optical sensor can also be used. In this
embodiment, a reflective surface is affixed to the truck frame and
the probe is equipped with a light emitter and receiver. When the
probe 10 moves near the reflective surface, the emitted light is
reflected back to the light receiver and a determination of the
position of the probe can be made. In yet another embodiment, a
sensor ball is confined in a cylinder having a first and a second
end. The cylinder may contain a liquid or gas in which the sensor
ball travels. Each time the sensor ball travels from the first end
to the second end of the cylinder and vice versa, one can deduct
that the probe is positioned in a certain direction. Once the ball
has travelled one way and back, this indicates that a complete
revolution of the mixer 2 was made. The processing unit 62 can also
use a chronometer to measure the time elapsed between each
revolution and thus can determine the speed of the probe 10. This
is to give some examples.
[0054] Reference is now made to FIG. 5, which is a schematic
diagram of vectors of accelerometers used to determine speed values
of the probe 10 in accordance with an embodiment. In FIG. 4, two
MEMS accelerometers 70, 72 are used, but it is understood that more
than two MEMS can be used to determine speed values of the probe.
The readings of accelerometers 70, 72 are typically the vector dot
product of the orientation vector of the accelerometers 70, 72 and
the total acceleration vector. For example, in FIG. 4, The
accelerometer 70 is oriented in the x axis direction while the
accelerometer is oriented in the y axis direction. Each
accelerometer orientation vector has a unit length, and the
gravitational acceleration is normalized to 1G (where G is the
gravitational acceleration). The accelerometer will respond to both
gravity and any other acceleration such as centripetal acceleration
and linear accelerations.
[0055] In one embodiment, a single accelerometer can be sufficient
to determine the probe angle relative to earth but the sign of the
angle is unknown. In this case, it would be possible to know that
the probe 10 is at the bottom of the mixer 2 to take the fluid
measurement, but the direction of the rotation would be unknown.
However, using the accelerometers 70, 72 with a 90 degrees angle
between them can provide the direction of the rotation. More
particularly, the second accelerometer (oriented circumferentially)
can provide this information and thus be used to determine rotation
direction of the mixer if desired.
[0056] In the case of an industrial mixer in which the axis of
rotation can be substantially vertical, a single accelerometer can
be used to provide the speed. Indeed, the mathematical integration
of the acceleration provides the speed and the change of direction
of the probe.
[0057] The details of an exemplary calculation using the
accelerometers is now provided in greater detail :
[0058] The accelerometer labeled x is in a radial orientation
(pointing away from the mixer circle), the accelerometer labeled y
other is in a tangent orientation. Assuming a constant rotation
speed, the only acceleration involved are the earth gravitational
acceleration (normalized so that |{right arrow over (g)}|=1 and the
centripetal acceleration. The x and y analog readings given by the
accelerometer can be as follows:
x = x -> ( g -> + a -> c G ) = x -> g -> + x -> a
-> c G = x -> g -> ( 1 ) y = y -> ( g -> + a -> c
G ) = y -> g -> + y -> a -> c G ( 2 ) ##EQU00001##
[0059] where: x=is the position of an accelerometer, [0060] {right
arrow over (x)}=the vector for the accelerometer, [0061] y=is the
position of an accelerometer, [0062] {right arrow over (y)}=the
vector of the orientation for the accelerometer, [0063]
G=gravitational acceleration, [0064] {right arrow over (g)}=the
vector for the gravitational acceleration, [0065] {right arrow over
(a)}.sub.c=the vector for the centripetal acceleration.
[0066] Because {right arrow over (x)} is perpendicular to {right
arrow over (a)}.sub.c, the accelerometer positioned at x is not
affected by the centripetal position. The equations (1) and (2) can
then be written as a function of the angle .theta. to give:
x = x -> g -> cos ( .theta. + .pi. 2 ) = - sin ( .theta. ) (
3 ) y = y -> g -> cos ( .theta. ) + y -> a -> c G cos (
.theta. ) = cos ( .theta. ) + a -> c G ( 4 ) ##EQU00002##
[0067] Given that in (3) and (4), the angle .theta. can be solved,
only if is |{right arrow over (a)}.sub.c| is known, but the value
depends on the angular rotation speed and the mixer radius. Those
values are unknown yet. However, if it is assumed that |{right
arrow over (a)}.sub.c|<G, then when x=0, .theta.=0 or .pi.. In
which case:
y = .+-. 1 + a -> c G = .+-. 1 + K ( 5 ) a -> c G = K = y y {
- 1 , when y > 0 + 1 , when y < 0 ( 6 ) ##EQU00003##
[0068] Thus, the offset is caused by the centripetal acceleration
can be determined at the minimum twice on each rotation, when
|{right arrow over (x)}|=0. That event can be easily detected in
software by monitoring the sign change of x.
[0069] A similar algorithm could be made for
.theta. = .pi. 2 or 3 .pi. 2 ##EQU00004##
but this would imply detecting when |{right arrow over (x)}|=1
which is difficult when any noise or offset is present in the
signal.
[0070] The rotational speed can be calculated, both in angular
notation .omega. in rad/sec, or in revolutions per minute (RPM) by
either monitoring the time elapsed between each revolution (when
.theta. crosses zero and checking before/after value to determine
the rotation direction), or by continuously computing
.omega. = .differential. .theta. .differential. t .
##EQU00005##
[0071] From equations 1 to 6 and the constant K, it is possible to
obtain an equation for r the radius of the mixer 2:
K = a -> c G = .omega. r 2 G ( 7 ) r = K G .omega. ( 8 )
##EQU00006##
[0072] From equation 8, r radius of the mixer 2 can be deduced and
v the linear speed at the center of the probe 10 can be
obtained.
r ' = r - 1 2 ( 9 ) v = .omega. r ' ( 10 ) ##EQU00007##
[0073] Where l=length of the probe in meters.
[0074] For example, the following parameters can be determined with
equations 7 to 10: the mixer instantaneous position, rotation speed
in revolutions per minute (rpm), the mixer rotation direction
(mixing or unloading), the mixer dimension, which can be determined
from the centripetal acceleration and the angular speed, the probe
linear speed, etc.
[0075] As described, the load cell 14 measures the force applied to
the outer member 13. For a given fluid mixture, that force
increases generally linearly with the speed. Because the total
force depends on the outer member dimensions and shape, it is
preferable to measure the average pressure applied by the fluid. To
avoid having a result that depends on the mixer size, the probe
linear speed is used. Then, the parameters of the probe 10 in
operation in the fluid can be determined by a proportional relation
between a pressure P and the linear speed v.
[0076] The linear speed v and the pressure are then simultaneously
obtained by the electronic module 18. The load cell 14 gives a
reading proportional to the force. The equation to calibrate the
load cell 10 to give an equivalent pressure P is obtained as
described below.
[0077] The torque T by a single force F applied at distance d from
a rotation axis is:
T=Fd (11)
[0078] If the force is generated by a pressure, for a small area,
the force F can be derived with dF=P dA. Then by integrating dF=P
dA, the torque T can be determined by a pressure on a finite plane
with effective width of W and length of L is given by:
T = .intg. 0 L P W x x = P W L 2 2 ( 12 ) ##EQU00008##
[0079] To calibrate the probe, it is thus possible to suspend a
calibration mass 80 from the probe when oriented horizontally.
Since the strain gauge 42 will give an analog reading proportional
to the force applied to the probe 10, a calibration is required to
retrieve the pressure. The calibration mass 80 is attached at a
distance d from the rotation axis defined by the base 11. The
torque T applied by the calibration mass 80 is:
T=Fd=mGd (13)
[0080] When the equations (12) and (13) are combined together, the
pressure is obtained with the following:
P = 2 mG L W = 2 F L W ( 14 ) ##EQU00009##
[0081] where:
[0082] P=pressure in kPa, [0083] m=mass in kg, [0084] G=gravity
(9.8 m/s2), [0085] L=probe length, [0086] W=probe effective
width,
[0087] d=distance of calibration mass from the rotation axis.
[0088] Reference is now made to FIG. 6A, which is an example of a
table of values obtained during a calibration of the load cell 14
in accordance with an embodiment. Equation (14) can be used to
build the calibration curve by applying many known masses,
measuring the electrical variation and determining the pressure,
given the known masses. In FIG. 6B, the values of the table of FIG.
6A are shown in a graphical representation of speed versus
pressure. In FIG. 6B, the pressure (in kPa) is determined using the
electrical variation of the probe 10 (in voltage).
[0089] Reference is now made to FIG. 7, which is a graphical
representation of the speed versus pressure values obtained during
the operation of the probe 10 in concrete at different speed
settings and over a limited period of time. The pressure applied on
the probe by the fluid was determined at different values of speed.
More particularly, there should be at least one value of pressure
(or the equivalent force), and preferably at least three, obtained
at a low speed range, and at least one value of pressure (or the
equivalent force), and preferably at least three, obtained in a
high speed range. Using these values, allows to plot an
extrapolated rheological curve, which can be done by the electronic
module 18 for instance. In an alternate embodiment, the probe can
emit these values and an electronic module for extrapolating the
rheological curve using these values can be provided externally, in
conjunction with a receiver, for instance. When approximating the
curve going through all determined points by a straight line 95
properties of the mixture such as, for example, the viscosity and
the yield of the fluid can be extracted.
[0090] The viscosity can be determined using the slope of the
straight line 95 passing through the points (or 1/slope of the
graph of FIG. 7).
[0091] The yield can be determined as well by extrapolating the
pressure at zero speed .tau..sub.0 using the straight line 95.
[0092] The probe 10 determines the viscosity and yield by
continuously monitoring the probe speed and automatically
performing a two point test when the probe is at the bottommost
point of its rotation in the fluid. The probe 10 determines
properties of the fluid and properties concerning the mixer 2 using
multiple ranges of speed. For example, the probe can determine
properties for the fluid using a low speed window and a high speed
window. This allows a realistic curve to be plotted. For example,
in the case of concrete in an average mixer truck, the low speed
window may comprise speeds between 0.25 and 0.75 m/s and the high
speed window may comprise speeds between 1.5 and 2 m/s. It will be
noted that the speed windows can greatly vary depending of
applications.
[0093] The probe 10 continuously monitors speed values and
determines pressure values each time the probe 10 is in operation
into the mixture of the mixer 2. If the current speed is inside the
low speed window, the pressure and speed are stored in the low
speed point memory 67. If the speed in inside the high speed
window, the pressure and speed are stored in the high speed point
memory 68. Each time a new high speed point is measured, the
processing unit 62 determines a straight line that passes through
the high and low speed points and determines the viscosity and
yield. Each time a low speed point is measured, the processing unit
62 determines the yield using the previously determined viscosity.
A proper calibration of the probe 10 using different compositions
of fluid, a lookup table or a curve fitting equation can be built
to determine the slump from the yield. With time, the rheological
equation will change. The points in the lower speed range will tend
to change more rapidly, and should be re-taken more frequently than
the points in the higher speed range.
[0094] The slump can be evaluated by:
Slump=k.tau..sub.0 (15)
[0095] where: [0096] k=constant, [0097] .tau..sub.0=pressure at a
zero speed.
[0098] Reference is now made to FIG. 8, which is a flow chart of a
method for determining properties of a fluid in the mixer 2 without
having to remove a sample of fluid from the mixer 2 and analyze it
externally. At step 1000, the processing unit 62 determines the
position of the probe 10 using at least one position sensor or
accelerometer. At step 1002, the processing unit determines that
the probe 10 is at the bottom position of the mixer 2. At step
1005, the processing unit 62 determines the pressure applied to the
probe 10 by the fluid. The processing unit 62 is in electronic
communication with the load cell 14. The load cell detects a
deformation of the outer member 13 resulting from a force applied
by the fluid on the probe 10. The load cell 14 then generates an
electrical variation, which is transmitted to the processing unit
62 which can interpret it to corresponding to a given pressure (or
corresponding force) applied by the fluid. The load cell reading
can be selectively obtained when the probe 10 is determined to be
immersed inside the substance, and optionally at or near the
bottommost position.
[0099] At step 1010, the processing unit 62 determines speed values
of the probe 10 using the determined position from the position
sensor or accelerometer. The force and pressure determined at step
1005 are thus determined at multiple ranges of speed values of the
probe 10. At step 1015 the probe 10 makes measurements using a low
speed window and At step 1020 the probe 10 makes measurements using
a high speed window. At step 1025, the probe 10 determines the
properties of the fluid based on speed values of the probe 10,
force values and pressure values when the probe 10 is in operation
in the mixer 2 and at the bottom point in the mixer 2. The
properties can be, for example, the viscosity and the yield of the
fluid. Then a rheological curve can be determined with the
viscosity and yield of the fluid. A slump can then be determined
using the yield without having to remove a sample of fluid from the
mixer 2 and analyze it externally. This allows the probe 10 to
determine the workability of the fluid, which can be further
wirelessly transmitted to the receiver 3. At step 1025, the
processing unit 62 continuously transmits the last computed data to
the receiver 3.
[0100] Referring back to FIG. 2, the radio transmitter 20 can
broadcast measurements and readings data of the sensors to the
receiver 3 at regular intervals. The measurements and readings data
can be combined with a probe unique serial number to create a radio
packet. The probe can use, for example, a radio carrier at 433 MHz
and a On-Off Keying (OOK) modulation technique to transmit the
radio packet, but it is understood that the radio frequency,
transmission power, transmission rates can be adjusted to
accommodate laws and regulations of different countries. The radio
range can be, for example, 30 to 50 meters. The serial number in
the radio packet uniquely identifies the probe from which the
measurements and readings data are sent.
[0101] The receiver 3 can be any wireless receiver that can
receive, store or process parameters measured with the probe 10. As
will be described below, various communication standards can be
used to transmit measurements and readings from the probe 10 to the
receiver 3.
[0102] The receiver 3 can include power means, a radio receiver
equipped with an antenna, a microcontroller having a memory and a
processing unit, a display (LCD display), a RS-232 serial port. The
receiver 3 also comprises a processor that processes data received
from the probe 10. For each received data, the receiver 3 verifies
the probe ID to identify from which probe data are received.
Instead of being fixedly mounted, the receiver can be mobile such
as hand held, for instance.
[0103] In one embodiment, the receiver 3 can be installed either on
a truck or is installed at a batching plant. If provided on the
truck, it filters the received data to keep only the data from the
probe on this truck. It provided at a batching plant, it will not
filter using the probe ID and will therefore monitor all the probes
that are in radio range. On a typical receiver 3, the raw sensor
readings such as the speed of a mixer, a pressure applied on a
probe, and a temperature are displayed in the screen for
information purposes.
[0104] The last rheological test results and workability
information (viscosity, yield and slump) can also be displayed.
Although the probe can monitor the speed of the mixer 2 to
automatically perform a two-point test, if the truck operator never
sets the speed in one of the speed window, the rheological curve
will not be updated. The display can also indicate if the
rheological curve is too old and guide the operator to activate the
mixer at a target speed and re-acquire the missing point.
[0105] In one embodiment, data can be sent to an output data port
(such as RS-232 serial port) which can be used by advanced logging
systems (truck or plant monitoring systems) to combine the probe
readings with other truck/plant operation readings for
instance.
[0106] In the illustrated example however, no further processing is
undertaken by the receiver 3 and the probe has already computed all
the calculations. However, nothing prevents the implementation of
other workability parameters computation algorithms using the raw
data from the sensors. For example, instead of a two-point
rheological test, a multiple-point rheological test can be made, or
different slump models can be implemented. The probe can also be
used for truck fleet management purposes. The mixer rotation
direction is a direct indication as to whether the truck is mixing
the fluid slowly (transit), fast (mix before delivery), or in
reverse direction (emptying the mixer, for example in a concrete
mixer truck embodiment).
[0107] In a system having a plurality of probes, which are used in
a close range scenario on the same or separate mixer units, a radio
receiver can distinguish from which probe the measurements and
readings data are sent from using that serial number.
Alternatively, any other unique identification number can be used
instead of the serial number. Besides OOK, other modulation
techniques can be used such frequency modulation (FM), phase
modulation (PSK) and narrow band modulations such as gaussian
frequency/phase shift keying (GFSK/GPSK). Complete standardized
radio systems such as Bluetooth and ZigBee could also be used.
Other wireless standards could be used, such as infrared
transmission and acoustical (ultrasound) data transmission.
[0108] In one embodiment, the processing unit 62 can transmit
different types of measurements such as the speed and the direction
of rotation of the mixer 2 to the receiver 3. The measurements can
be sent in a radio data packet identified with an identification
number of the probe 10. Therefore, each time the receiver 3
receives a radio data packet from a same probe it may increment a
sequential number incremented for each radio transmission. Then the
receiver 3 can determine, a last read temperature, the last read
speed of the mixer, The last read point (pressure, speed, age), the
last known low-speed point (pressure, speed, age), the last known
high-speed point (pressure, speed, age), the last computed
workability parameters (yield, viscosity, slump, age), and a
checksum or CRC (cyclical redundancy check) for data integrity. The
age refers to a period in time and the number of times a
measurement was made. The receiver 3 can use the information for
example, as a timestamp to inform a user of an age of measurements,
which can be too old or not valid anymore depending on a certain
threshold.
[0109] The speed direction can determine whether the mixer 2 is
empty. The mixer 2 can be determined to be empty when, for example,
a number of revolutions have been made by the mixer 2 at high or
constant speed in a certain unloading direction. Alternatively, the
mixer can be determined to be empty when the force sensor does not
detect resistance by the fluid.
[0110] The rotation direction of the mixer 2 can be used when
loading the mixer 2, for example, at a batching plant. When the
rotation direction is adequate, a batching plant operator can
safely load the concrete into the mixer without spillage of
concrete. Alternatively, the readings from the probe 10 can also be
used directly by the batching plant operator (or software) to set a
condition to start loading the concrete into the mixer 2.
[0111] Those skilled in the art will understand that the probe 10
is not necessarily limited to the number of elements shown in FIGS.
3 and 4. For example, the probe 10 may comprise more load cells or
sensors. More particularly, it should also be understood that FIGS.
3 and 4 depict simplified hardware and software parts, and that
other hardware and software parts may have been omitted for clarity
reasons. Those skilled in the art will understand that the hardware
parts of the probe 10 include processors and electronic parts to
execute the method described above. Those skilled in the art will
understand that the software parts of the probe 10 include
instructions and computer code that are executed by the processors
and electronic parts to process the measurements and readings made
by the probe 10, to determine properties for the fluid and to
transmit data to a receiver.
[0112] Turning now to FIG. 9, another embodiment of a probe 110 is
shown. In this embodiment the resistance member 112 also includes
an inner member 114 and an outer member 116 (or shell). The inner
member 114 is fixed to and extends away from the base 118. It can
be said to have successively a base portion 120 adjacent the base
118, a deformation portion 122, and a tip 124. The shell 116
entirely covers the inner member 114 and collectively with the base
118, prevents intrusion of the substance to characterize. It can be
pivotally mounted near the base, and fixedly connected at the tip
124, to allow transmission of a force F caused by the frictional
resistance or pressure of the substance along the length of the
shell (as the probe is immersed and is being displaced relative to
it) onto the inner member 114 in a manner to deform the deformation
portion 122. The deformation portion 122 can have a strain gauge to
obtain an indication of the deformation of the deformation portion
122 and thus an indication of the force F. In this example, the
pivoting is achieved by mounting the lower end of the shell 116 in
a tight fit manner around an annular bushing 130 provided around
the base portion 120 of the inner member 144 rather than by using a
pivot shaft for instance. This can be advantageous in providing a
more direct reading which can be lost in cases where a loose pivot
shaft is used given the size of the deformations envisaged here.
The pivot axis 126 of the shell can thus be said to go across the
inner member 114 and bushing 130 in this case.
[0113] In this particular example, the deformation sensor can have
a load cell including one or more strain gauges for instance. Using
two strain gauges on opposite sides can potentially allow better
reading the resistance force in both directions and even
determining the rotation direction of the drum otherwise than by
the use of an extra accelerometer. The strain gauge 128 is provided
on a flat, relatively easy to deform portion of the inner member
114 to optimize measurements given the capacity of the strain gauge
128. The wire 132 connecting the strain gauge to an electronic
module can pass through a hollow in the inner member 114, for
instance. The deformation portion 122 can thus be specifically
designed to offer elastic deformation up to a predetermined maximum
reading value. In this specific example, the deformation portion is
machined into a hollow steel pipe to form two parallel flat metal
portions.
[0114] To protect the deformation portion 122 from going into the
plastic deformation range if ever the maximum estimated force is
exceeded, the inner member 114 can be provided with an abutment
portion 134 below the deformation portion 122, which abuttingly
receives the shell 116 in the event the maximum deformation is
reached, and prevents transmission of further force, to prevent
further deformation.
[0115] Alternately to a deformation sensor, for instance, it will
be understood that a pressure sensor can be used between the inner
member and shell to achieve a comparable result, for instance.
[0116] Turning now to FIG. 10, an alternate embodiment of a probe
210 is shown. In this case, the probe has a force sensor 212 (or
pressure sensor) to obtain a value indicative of the pressure
exerted by the substance on the resistance member, and a speed
sensor 214 to obtain a value indicative of the speed of
displacement of the probe 210 relative the substance. A rheological
value calculator 216 can be used to determine a value indicative of
at least one rheological property of the substance based on the
force value and the speed value for instance. To obtain values
indicative of yield and viscosity, for instance, the rheological
value calculator can use at least one force value and speed value
combination corresponding to a moment in time in a low speed range,
and at least one force value and speed value combination
corresponding to a moment in time in a high speed range. To this
end, these values can be stored in a memory 218 for use by the
rheological value calculator 216. The rheological value(s) can be
transferred along to an emitter 220, which can transmit data
wirelessly to a receiver 222 for instance, which can be connected
to a display 224 for instance.
[0117] The speed sensor can be any suitable speed sensor. One
example can include a position sensor 230 such as an accelerometer
for instance, connected to a speed calculator 232 which calculates
the speed based on the variation of position over time, to provide
one example. In an alternate embodiment, the speed calculation and
the rheological value calculation can be done by a single
processing unit.
[0118] The probe 210 can further include a temperature sensor 226
for instance or one or more other sensors. The data from the
temperature sensor 226 can also be emitted by the emitter 220. The
probe will typically include a power source 228 which can provide
power to any module which requires power in the probe.
[0119] In an alternate embodiment, the emitter can be omitted and
the data can be obtained directly from a port or an indicator which
can be provided in the base of the probe for instance, or the
emitter can be a wired emitter instead of a wireless emitter for
instance. In another alternate embodiment, the rheological value
calculator can be provided externally to the probe, and the emitter
can transmit primary data such as force data, speed data, or
position data for instance.
[0120] The embodiments described above are intended to be exemplary
only. The scope of the invention is therefore intended to be
limited solely by the scope of the appended claims.
[0121] Now that the invention has been described,
* * * * *