CA1197705A - Procedure for opto-electronic identification of the combustion line of the wrapper encasing a smokable article, and apparatus for carrying out this procedure - Google Patents
Procedure for opto-electronic identification of the combustion line of the wrapper encasing a smokable article, and apparatus for carrying out this procedureInfo
- Publication number
- CA1197705A CA1197705A CA000415015A CA415015A CA1197705A CA 1197705 A CA1197705 A CA 1197705A CA 000415015 A CA000415015 A CA 000415015A CA 415015 A CA415015 A CA 415015A CA 1197705 A CA1197705 A CA 1197705A
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- Canada
- Prior art keywords
- ssa
- units
- set forth
- output
- voltage
- 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
- 238000002485 combustion reaction Methods 0.000 title claims abstract description 47
- 230000005693 optoelectronics Effects 0.000 title claims abstract 3
- 238000000034 method Methods 0.000 title abstract description 7
- 235000019504 cigarettes Nutrition 0.000 claims description 17
- 230000000391 smoking effect Effects 0.000 claims description 14
- 230000033001 locomotion Effects 0.000 claims description 9
- 238000006073 displacement reaction Methods 0.000 claims description 5
- 230000007704 transition Effects 0.000 claims description 5
- 230000010363 phase shift Effects 0.000 description 7
- 239000000463 material Substances 0.000 description 6
- 230000006399 behavior Effects 0.000 description 4
- 238000005979 thermal decomposition reaction Methods 0.000 description 4
- 238000010586 diagram Methods 0.000 description 3
- 230000000694 effects Effects 0.000 description 3
- 230000001419 dependent effect Effects 0.000 description 2
- 238000013461 design Methods 0.000 description 2
- 238000011156 evaluation Methods 0.000 description 2
- 238000011835 investigation Methods 0.000 description 2
- 150000002500 ions Chemical class 0.000 description 2
- 239000000779 smoke Substances 0.000 description 2
- 230000001960 triggered effect Effects 0.000 description 2
- 101100128278 Mus musculus Lins1 gene Proteins 0.000 description 1
- 230000006978 adaptation Effects 0.000 description 1
- 230000001276 controlling effect Effects 0.000 description 1
- CVSVTCORWBXHQV-UHFFFAOYSA-N creatine Chemical compound NC(=[NH2+])N(C)CC([O-])=O CVSVTCORWBXHQV-UHFFFAOYSA-N 0.000 description 1
- 238000010348 incorporation Methods 0.000 description 1
- QHGVXILFMXYDRS-UHFFFAOYSA-N pyraclofos Chemical compound C1=C(OP(=O)(OCC)SCCC)C=NN1C1=CC=C(Cl)C=C1 QHGVXILFMXYDRS-UHFFFAOYSA-N 0.000 description 1
- 230000005855 radiation Effects 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 238000009423 ventilation Methods 0.000 description 1
- 230000000007 visual effect Effects 0.000 description 1
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01B—MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
- G01B7/00—Measuring arrangements characterised by the use of electric or magnetic techniques
- G01B7/02—Measuring arrangements characterised by the use of electric or magnetic techniques for measuring length, width or thickness
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
- G01N21/17—Systems in which incident light is modified in accordance with the properties of the material investigated
- G01N21/55—Specular reflectivity
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01P—MEASURING LINEAR OR ANGULAR SPEED, ACCELERATION, DECELERATION, OR SHOCK; INDICATING PRESENCE, ABSENCE, OR DIRECTION, OF MOVEMENT
- G01P3/00—Measuring linear or angular speed; Measuring differences of linear or angular speeds
- G01P3/64—Devices characterised by the determination of the time taken to traverse a fixed distance
- G01P3/68—Devices characterised by the determination of the time taken to traverse a fixed distance using optical means, i.e. using infrared, visible, or ultraviolet light
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Health & Medical Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- Chemical & Material Sciences (AREA)
- Analytical Chemistry (AREA)
- Biochemistry (AREA)
- General Health & Medical Sciences (AREA)
- Immunology (AREA)
- Pathology (AREA)
- Manufacturing Of Cigar And Cigarette Tobacco (AREA)
- Photometry And Measurement Of Optical Pulse Characteristics (AREA)
Abstract
ABSTRACT
Procedure for opto-electronic identification of the combustion line of the wrapper encasing a smokable article, and apparatus for carrying out this procedure.
Procedure for opto-electronic identification of the combustion line of the wrapper encasing a smokable article, and apparatus for carrying out this procedure.
Description
7~7~3~
Description The inven-tion relates to a procedure and an apparatus for identifying the combustion line of -the wrapper encasing a smokable article (in particular the combustion line of cigarette paper, wrapper leaf or synthetic wrapper).
DE-OS 2 947 249 (German Patent Application) published May 27, 1981 describes a method for determining the rate of combustion and/or glow of a smokable article whereby a sensor capable of detecting the radiation from the incandescent zone of the smokable article is made to travel parallel with the movemen-t of that zone, while the exact position of the sensor along the path of travel is plottéd in relation of time by means of an electrical signal. By this means it is possible to determine the location of the lncandescent zone throughout the period during which the smokable article is being smoked - i.e.
during puffs and during the intervals between puffs -thus enabling the rate of combustion and/or glow to be ascertained.
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Apart from the rate of combustion and/or glow,-a further important parameter for a smokable article such as a cigarette is the behaviour of the wrapper material - for example, cigarette paper, wrapper leaf or synthetic wrapper - during thermal decomposition.
The thermal decomposition behavioux can be influenced by the choice of appropriate materials, which in turn have a corresponding influence on the actual line of combustion, i.e. the point of transition between the ash and the unburnt wrapper material. Among the factors which can be influenced by the thermal decomposition behaviour - and thus by the speed of advance of th~
combustion line - are the puff resistance of the conical incandescent zone, the degree of ventilation of the buxning smokable article, the rate of combustion and the smoke yield.
The recognized method for determining the rate of combustion and/or glow of the incandescent zone is not suitable for plotting the advance of the combustion line due to the fact that the combustion line precedes the area of maximum incandescent-zone temperature by a certain distance, i.e. there i5 no direct correlation between the rate of combustion and/or glow on the one hand and the advance of the combustion line on the other~
In practice, therefore, it has hitherto not been possible to monitor the advance of the combustion line except by purely visual means.
The preserlt inv~nt:;(.)~î w.~ tnc.~e:to:r.e clevi.secl ~J:ith the aim oE creatin~ an apparatus Eor iclentifying the com-bus-tion line o~ a srnokable ar-ticle (in particular the eomb~stion line of cigare-t-te paper, wrapper leaf or synthetic wrapper) in such a way tha-t the movement of the combustion line can be plotted or reeorded by fully automatie means.
In particular the invention is designed to determine and reeord the combustion line throughout the entire smoking proeess, i.e. not only in the intervals between puffs but during the puff phases as well.
Aceerdingly, the present invention is an apparatus for opto-eleetronie identifieation of the eombustion line of the wrapper eneasing a smokable artiele (in partic-ular the eombustion line of eigarette paper, wrapper leaf or syn-thetie wrapper) whieh incorporates two source and sensor assembly units (hereinafter SSA units) positioned side by side for moving in the direetion of travel of -the eombustion line for refleetive sensing ~0 applications, a subtracter for the output signals from the sensors of the two SSA units, and a device for detect-ing a sudden differenee in the output signals from the SSA units at the point of transition from ash to wrapper at the combustion line.
The benefits of this invention derive from the exploita-tion of the fact tha-t the wrapper material (e.g. eicJarette paper), the eombustion line and the ash produced by the burnin~ tobaeeo in the ineandescent zone all possess vtd/~
7~S
different refl.ective characteristics. These character-istics are determined and recorded by source ancl sensor assembli.es for reflective sensiny applications (herein-after referred to as SSA or SSA units).
- 3a vtd/ ~
~ ~ ~3 ~ ~ V ~i An electronic analyzin~ device records the glow rate of the combustion lins during the inkervals between puffs, as well as the speed of advance of the combustion line during the puff phases.
By using this apparatus it is therefore possible to carry out investigations into the influence of various wrapper materials - e~g. cigarette papers to which certain substances have been added - on the thermal decomposition behaviour of the wrapper, as well as investigations into other important parameters for smokable articles.
The degree of reflectance of the surface of the smokable article ~ i.e. of its wrapper material ~oyb~
~5 determined b~ means of a commercially available SSA unit which utilizes a light emitting diode (LED) operating at infrared frequencies as a transmitter and a suitable phototransistor as a receiver. The measured signal caused by a change in the degree of reflectance of the surface of the smokable article is subject to two disturbance variables, namely a variation in the distance between the surface of the smokable article and the SSA unit~
and the infrared emission from the incandescent zone of the smokable article.
~ 5 - f~L~
The effect of any varlations in distance between the SSA unit and the smokable article is almost entirely offse-t by utiliziny two SSA units mounted side by side and by computing the difference in the signals received by the two units~
The infrared emission from the incandescent zone of the smokable article in1uences the opto~electronic xeceiver of the SSA unit. However, as ~he infrared emission from the incandescént zone is continuous, it is possible to compensate for any error by con-trolling the LEDs of the SSA unit with a sinusoidal AC voltage supply wich is shifted upwards by a constant DC
voltage~
If the alternating components~of the received signals are then isolated and rectified after determination -of the diference in signal, the result is a voltage which is proportional to the di~ference in the degree of reflectance at the points scanned by the two SSA
units.
Fluctuations in the perormance of the two SSA units result in a phase shift between the two received signals.
This phase shift can be offset by means of a phase shifter incorporated in the transmitter circllit of one of the SSA units. If thls phase shift is not offset, 3'77'~
the difference between the two signals - even if the degree of reflectance at the two points scanned is the same - is sufficient to generate a relatively high output voltage, which in turn results in instrument error~
As the smokable article is normally attached rigidly to the smoking machine, and cannot therefore be moved, m~>y 1~
the SSA units a~e mounted in such a way that they can travel forward in accordance with the movemen~ of the combustion line~ The SSA units are therefore moved via a rack and pinion gear which is driven by an electric motor.
This motor is controlled in such a way that it moves the two SSA units bacK and forth over a range within which the analyzed output signal fromthe two units does not fall below a c~rtain minimum limit. In one preferred design this minimum limit lies above the zero-signal level of the two SSA units.
This constant back-and-forth movement of the motor -and hence of the two SSA units - in ~he vicinity of the combustion line produces a sufficiently larye number of readings for accurate analysis and evaluation.
During the puff phase the infrared emissisn from the incandescent zone of the smokable article is so powerful that the phototransistor of the SSA unit closest to the incandescent zone exceeds saturation point and therefore ceases to deliver any signal. By means of a time switch the motor is therefore triggered by the smoking machine in such a way that the two SSA
units are moved slightly faster during the puff phase than the actual speed of the combustion line.
Immediately after the puff the infrared emission from the incandescent zone falls to a level where the combustion line can once again be identified by the SSA unit directly in line with it.
The position of the motor which moves the two SSA units thus serves to indicate the position of the two SSA
unitsO A potentiometer coupled to the motor and connected to a refexence voltage supply thus delivers an output voltage which is in proportion to the position of the SSA units~ This output voltage is then registered by means of an x-t recorder, thus providing a direct indication of the rate of progress of the combustion line.
3'~
The incorporation of further switching devices makes it possible to plot the position/time curve of the SS~ units, and thus ko plot the forward movement of the combustion line at a series of points~
The invention is describ0d in more detail below with reference to a prototype model as specified in the attached graphs and diagrams. These gra~hs and diaarams are as follows:
Fig. 1 General view of the apparatus for identifying the combustion line of a cigarette Fig. 2 Block writing diagram of the electronic circuitry for the apparatus as shown in Fig. 1 Fig. 3 Perspective view of the two SSA units Fig~ 4 Graphs showing the output signals from the two SSA units without phase shift Fig. 5 The non-rectified diffe.rence signal from the two and 6 SSA units where the degree of reflectance is the same at the two points scanned Fig~ 7 The difference signal at the poin~ where the combustion llne is identified Fig. 8 Time curve for the voltage U as the combustion line passes in front oE the stationary SSA units Fig. 9 ~raph representing the fluctuations .in the voltage Um and the limiting values (-to be explained subsequently) Fig. 10 Graph representing the movement of the combustion line of a cigarette during smoking Figure 1 shows the general design of an apparatus for identifying the combustion line of a cigarette. The cigarette consists of an incandescent zone ~13, the paper combustion line which is to be monitored ~2), the cigarette strand ~3) and a filter (4), which is clamped into a standard holder (5). The holder (53 is inserted into a smoking machine (6~, which can be programmed to "smoke" the cigarette according to a pattern that simulates the behaviour of a human smokerO
Parallel to the cigarette is a toothed rack (93, on which is mounted a sliding head carrying two SSA units (RL 1, RL 2) positioned side by side. The rack ~33 can be rotated by means of an electric motox (113, thus causing the two SSA units (RL 1, RL 2) to move parallel with the ciyarette. A displacement transducer (10~
--' lC -is connected either to the motor (11) or to the rack (9). The output signal of the displacement transducer (10) is proportional to the rotation of the rack (9~/electric motor (11~ and thus to the position of the SSA units ~RL 1, RL 2).
The output signals from the two SSA units, i.e.
the received signals, are fed in-to an analyzing device 112), which controls the motor via a control unit ~13~ and receives the signal from the displacement transducer (10). The analyzing device (12) is connected to a recording device (14~ n Figure 3 shows a perspective view of the two SSA units ~RL 1, RL 2), each of whi.ch contains a light-emitting diode operating at infrared frequencies as a t.ransmitter, and a suitable phototransistor (F~) which receives the light reflected from the surface of the cigarette. In order to ensure that ~he points scanned by the two SSA units (RI. 1, RL 2) are as close together as possible, an adjusting wedge (35) is posi-tioned between the two units (R~ 1, RL 2) in such a way that it maintains the units (RL 1, RL 2) at a predetermined angle to each other. This angle is 13 in the cas~ of the apparatus described.
' 1 1 ~
The two SSA units (RL 1 and ~L 2) are mounted toyether on the toothed rack ~9) by means of an attachment and can be made to move parallel with the ciyarette.
If only one SSA unit were to be used, any varia~ion in the distance between this single unit and the cigare-tte would result in a corxesponding change in the received signal. In order to minimize this effect, the apparatus described utilizes two SSA units (RL 1, ~L 2) so that any variations in distance can be almost completely offset by computing the difference between the two signals (E1 and E2) received by the two units.
As can be seen from Figure 2, the two SSA units (RL 1 RL 2~ are ed from a constank voltage source 515) which supplies a DC voltage (U1) and from a generator ~163 which supplies a ~inusoidal AC voltage. Th~
sinusoidal AC voltage from the generator (16~ and the DC voltage tU1) are fed into the first subtracter 517 so that the LEDs (transmitters) of the kwo SSA units (RL 1f RL 2) are driven by a sinusoidal AC voltage which is shifted upwards by the DC voltage U1.
7~
, The output of the subtrac~er t17) is linked to a junction (18), which is connected directly to the first SSA unit (RL 1) and via an all-pass network 519) to the second SSA unit (RL 2~. This all-pass network compensates for -the phase shifts between the two received signals caused by fluc~uations in the performance of the two units. Figure 4 shows the phase shift between the two received signals which occurs when the transmitters of the two SSA units (RL 1I RL 2) are powered directly by the supply voltage, The difference between these two signals - even if the degree of reflec-tance at the two points scanned is the same ~ would be sufficient to genera~e a relatively high output voltage r thus resulting in a faulty reading.
For this reason the phase shift must be offset by means of the all-pass network (19).
The light emitted from the LEDs (transmitters) is reflected from the surface of the cigarette and picked up by the phototransistors, which generate an output signal in proportion to the degree of reflectance at the surface of the cigarette. The output signals from the phototransistors are then fed into two high-pass filters ~20 and 21), thus isolating the alternating components of the received signals E1 and E2. These signals are then converted.
7t~3~
By feeding the two transmitters wi~h the sinusoidal AC voltage which is shifted upwards by the DC supply voltage U1~ it is possible to distinguish between the reflected infraxed light and the infrared emission from the incandescent zone, which con-tinuously irradiates the two receiversO
The outpu~ signals from the two high-pass filters ~20 and 21) - i.e. the alternating components of the signals received by the two 5SA units ~RL 1 and ~L 2) -are fed into a second subtracter (22~, which produces the difference between the two output signals. This difference is then amplified by means of an amplifier (23) and fed into a rectifier (24), the output signal from which represents the actual voltage IUm3, i.e. a voltage which is in proportion to the difference in the degree of reflectance ( ~3 at the points scanned by the two SSA units ~RL 1, RL 2)o Figures 5 and 6 show the two received signals E1 and E2, i.e~ ~he output signals from the two SS~ units (RL 1 and RL 2). In Figure 5 the two signals are shown in phase, while in Figure 6 they are in phase oppostion.
Figures S and 6 also show the non-rectified difference signal, i.e. the difference between the two received singals E1 and E2 when the degree of reflectance (~
is the same at the two points scanned.
Figure 7 shows the non-rectifled difference signal for the two received signals (E1 and E2) in phase opposition when the combustion line is identifiedO
This signal is the result of the difference in the degree of reflectance of the ash and that of the unburnt paperO
The difference signals sho~n in Figures 5 to 7 are thus generated at the output of the second subtracter (22).
After rectification in the rectifier (24), the voltage Um can be registered by a meter. Figure 8 shows the curve for the voltage Um as the paper combustion line passes in front of the two stationary SSA units (RL 1 and ~L 2). The graph shows an obvi~us peak which marks the transition between the two reflecting zones, i.e. the ash and the surface of the paper. As explained above, this sudden transition is due to the different degrees of reflectance (3 3 at the two points scanned.
If the two points scanned by the two SSA units (RL 1 and RL 2] are both located on the ash or the paper surface~ the difference signal will fall to zero, or approximately zero, as is shown in Figures 5 and 6 together with Figure 8. Figure 8 also shows a number t~J~ r ~
of levels (1L, 2L, 1H, 2H) on either side o~ the peak value for UmO These levels are selected at random on the sole condition that they lie above the apparatus noise threshold.
The output signal from the rectifier (24), i~eO the voltage Um, is applied via two junctions ~25 and 27 to two Schmitt triggers (26 and 28). One of these Schmitt triggers (26) is linked via a junction (29) to a third subtracter (31). With the aid of a voltage source U2 (32) the speed of forward and reverse movement can be varied. The output signal from the subtracter (31) is applied via an amplifier (33) to the motor 111). The Schmitt trigger (26) :is controlled when the rectified difference between the signals E1 and E2 received by the two 5S~ units (RL 1 and RL 2l - iOe.
the voltage Um - is less than 2L and greater than 2H
(see figures 8 and 9), thus causing the motor (11) to move the two SSA units (RL 1 and RL 2) back and forth in such a way that the voltage (Um) always remains within the range defined ~y these two extreme values. Figure 9 shows the corresponding switch-over points t2L and t2H~
which are dependent on the output voltage Ux2 from the Schmitt trigger ~26~.
7(~5i The constant rotation and counter-ro~a~ion of th~
motor (11) ~ which effects a corresponding back-and-forth movement of the two SSA units (RL 1 and RL 2~ -provides a sufficientl.y large number of readings for accurate evaluation and analysis.
During the puff phase, i.e. while the smoking machine (6) is in operation, the infrared emission from the incandescent zone (1~ is so powerful that the phototransistor (FT) of the SSA unit closest to that zone exceeds saturation point and therefore ceases to deliver a measurable signal.
By means of a time switch (not shown) the motor ( 11 ) is then triggered by the smoking machine in such a way that it causes the two SSA units (RL 1 and RL 2) to move slightly faster during the puff phase than the actual speed of advance of the combustion line.
In Figure 2 this adaptation is indicated by a transducer l34~, which is linked both to the third subtracter (31) and to the smoking machine (6) 7 This transducer (34) serves to trigger the mo-tor (11) via the smoking machine (6) during the puff phases~
7~5 Immediately following the end of a puff phase the infrared emission from the incandescent zone falls to a level where the combustion line (2) -with which the SSA units are still aligned -can once again be detected.
The two SSA units are displaced via the too-thed rack (9j (indicated in the diagram by a dotted line) by the motor (11), which is controlled accordingly by the voltage Um and the Schmitt trigger (26).
Either the rotation of the motor (11) or the position of the rack ~9) therefore serves to indicate the position of the two SSA units (RL 1, RL 2). For this purpose a displacement transducer (10) - e.gO a potentiometer connected to a reference vol-tage supply -is coupled to the motor (11) or to the rack (9).
This potentiometer delivers an output voltage which is in proportion to the position of the two SSA units iRL 1 and RL 2)o The output voltage is registered by a recording device (14) (e.g. an x-t recorder3, thus providing a direct indication of the rate of advance of the paper combustion lineO
As explained above, the Schmitt trigger 126) switches between the two values 2L and 2H (see Figure 8)o The second Schmitt trigger (28), which receives the ~'7~S
voltage Um via the junction (27~, swi.tches between the values 1L and 1H 5see Figure 8), so that the two Schmitt triggers (26 and 28~ generate the corresponding output voltages U 1 and U 2~ These two output voltages Uxl and Ux2 are then fed into a logic unit (30), either directly via the second Schmitt trigger (28), or indirectly via the first Schmitt trigger (26) and the junction (291, The logic unit (30) combines the two output signals x1 and x2 in accordance with the following logical function:
Y ~ X2 The output signal y from the logic unit (30~ is then fed to the pen lift connection o the x-t recorder (14).
The logic combination of the two output signals as described makes it possible to present the curve as a series of separate points due to the fact that the pen of the x~t recorder (14~ only traces the curve when the two SSA units (RL 1 and RL 2) are located between the two limiting values 1L and 2L and are moving towards 2Lo The corresponding switch-over points t1L and t1~ which are dependent on the output voltage Ux1 from the second Schmitt trigger, are indicated .in F:igure 9.
7~
~ 19 -Finally, Fig. 10 shows the movement of the combustion line of a cigarette, as recorded by the two SSA units (RL 1 and RL 2) moving parallel with the incandescent zone. The breaks in the curve caused by the lifting of the pen can be clearly seen.
Description The inven-tion relates to a procedure and an apparatus for identifying the combustion line of -the wrapper encasing a smokable article (in particular the combustion line of cigarette paper, wrapper leaf or synthetic wrapper).
DE-OS 2 947 249 (German Patent Application) published May 27, 1981 describes a method for determining the rate of combustion and/or glow of a smokable article whereby a sensor capable of detecting the radiation from the incandescent zone of the smokable article is made to travel parallel with the movemen-t of that zone, while the exact position of the sensor along the path of travel is plottéd in relation of time by means of an electrical signal. By this means it is possible to determine the location of the lncandescent zone throughout the period during which the smokable article is being smoked - i.e.
during puffs and during the intervals between puffs -thus enabling the rate of combustion and/or glow to be ascertained.
~,. ... ..
kh/ ~
d ~:A~`Jr^1~t~
Apart from the rate of combustion and/or glow,-a further important parameter for a smokable article such as a cigarette is the behaviour of the wrapper material - for example, cigarette paper, wrapper leaf or synthetic wrapper - during thermal decomposition.
The thermal decomposition behavioux can be influenced by the choice of appropriate materials, which in turn have a corresponding influence on the actual line of combustion, i.e. the point of transition between the ash and the unburnt wrapper material. Among the factors which can be influenced by the thermal decomposition behaviour - and thus by the speed of advance of th~
combustion line - are the puff resistance of the conical incandescent zone, the degree of ventilation of the buxning smokable article, the rate of combustion and the smoke yield.
The recognized method for determining the rate of combustion and/or glow of the incandescent zone is not suitable for plotting the advance of the combustion line due to the fact that the combustion line precedes the area of maximum incandescent-zone temperature by a certain distance, i.e. there i5 no direct correlation between the rate of combustion and/or glow on the one hand and the advance of the combustion line on the other~
In practice, therefore, it has hitherto not been possible to monitor the advance of the combustion line except by purely visual means.
The preserlt inv~nt:;(.)~î w.~ tnc.~e:to:r.e clevi.secl ~J:ith the aim oE creatin~ an apparatus Eor iclentifying the com-bus-tion line o~ a srnokable ar-ticle (in particular the eomb~stion line of cigare-t-te paper, wrapper leaf or synthetic wrapper) in such a way tha-t the movement of the combustion line can be plotted or reeorded by fully automatie means.
In particular the invention is designed to determine and reeord the combustion line throughout the entire smoking proeess, i.e. not only in the intervals between puffs but during the puff phases as well.
Aceerdingly, the present invention is an apparatus for opto-eleetronie identifieation of the eombustion line of the wrapper eneasing a smokable artiele (in partic-ular the eombustion line of eigarette paper, wrapper leaf or syn-thetie wrapper) whieh incorporates two source and sensor assembly units (hereinafter SSA units) positioned side by side for moving in the direetion of travel of -the eombustion line for refleetive sensing ~0 applications, a subtracter for the output signals from the sensors of the two SSA units, and a device for detect-ing a sudden differenee in the output signals from the SSA units at the point of transition from ash to wrapper at the combustion line.
The benefits of this invention derive from the exploita-tion of the fact tha-t the wrapper material (e.g. eicJarette paper), the eombustion line and the ash produced by the burnin~ tobaeeo in the ineandescent zone all possess vtd/~
7~S
different refl.ective characteristics. These character-istics are determined and recorded by source ancl sensor assembli.es for reflective sensiny applications (herein-after referred to as SSA or SSA units).
- 3a vtd/ ~
~ ~ ~3 ~ ~ V ~i An electronic analyzin~ device records the glow rate of the combustion lins during the inkervals between puffs, as well as the speed of advance of the combustion line during the puff phases.
By using this apparatus it is therefore possible to carry out investigations into the influence of various wrapper materials - e~g. cigarette papers to which certain substances have been added - on the thermal decomposition behaviour of the wrapper, as well as investigations into other important parameters for smokable articles.
The degree of reflectance of the surface of the smokable article ~ i.e. of its wrapper material ~oyb~
~5 determined b~ means of a commercially available SSA unit which utilizes a light emitting diode (LED) operating at infrared frequencies as a transmitter and a suitable phototransistor as a receiver. The measured signal caused by a change in the degree of reflectance of the surface of the smokable article is subject to two disturbance variables, namely a variation in the distance between the surface of the smokable article and the SSA unit~
and the infrared emission from the incandescent zone of the smokable article.
~ 5 - f~L~
The effect of any varlations in distance between the SSA unit and the smokable article is almost entirely offse-t by utiliziny two SSA units mounted side by side and by computing the difference in the signals received by the two units~
The infrared emission from the incandescent zone of the smokable article in1uences the opto~electronic xeceiver of the SSA unit. However, as ~he infrared emission from the incandescént zone is continuous, it is possible to compensate for any error by con-trolling the LEDs of the SSA unit with a sinusoidal AC voltage supply wich is shifted upwards by a constant DC
voltage~
If the alternating components~of the received signals are then isolated and rectified after determination -of the diference in signal, the result is a voltage which is proportional to the di~ference in the degree of reflectance at the points scanned by the two SSA
units.
Fluctuations in the perormance of the two SSA units result in a phase shift between the two received signals.
This phase shift can be offset by means of a phase shifter incorporated in the transmitter circllit of one of the SSA units. If thls phase shift is not offset, 3'77'~
the difference between the two signals - even if the degree of reflectance at the two points scanned is the same - is sufficient to generate a relatively high output voltage, which in turn results in instrument error~
As the smokable article is normally attached rigidly to the smoking machine, and cannot therefore be moved, m~>y 1~
the SSA units a~e mounted in such a way that they can travel forward in accordance with the movemen~ of the combustion line~ The SSA units are therefore moved via a rack and pinion gear which is driven by an electric motor.
This motor is controlled in such a way that it moves the two SSA units bacK and forth over a range within which the analyzed output signal fromthe two units does not fall below a c~rtain minimum limit. In one preferred design this minimum limit lies above the zero-signal level of the two SSA units.
This constant back-and-forth movement of the motor -and hence of the two SSA units - in ~he vicinity of the combustion line produces a sufficiently larye number of readings for accurate analysis and evaluation.
During the puff phase the infrared emissisn from the incandescent zone of the smokable article is so powerful that the phototransistor of the SSA unit closest to the incandescent zone exceeds saturation point and therefore ceases to deliver any signal. By means of a time switch the motor is therefore triggered by the smoking machine in such a way that the two SSA
units are moved slightly faster during the puff phase than the actual speed of the combustion line.
Immediately after the puff the infrared emission from the incandescent zone falls to a level where the combustion line can once again be identified by the SSA unit directly in line with it.
The position of the motor which moves the two SSA units thus serves to indicate the position of the two SSA
unitsO A potentiometer coupled to the motor and connected to a refexence voltage supply thus delivers an output voltage which is in proportion to the position of the SSA units~ This output voltage is then registered by means of an x-t recorder, thus providing a direct indication of the rate of progress of the combustion line.
3'~
The incorporation of further switching devices makes it possible to plot the position/time curve of the SS~ units, and thus ko plot the forward movement of the combustion line at a series of points~
The invention is describ0d in more detail below with reference to a prototype model as specified in the attached graphs and diagrams. These gra~hs and diaarams are as follows:
Fig. 1 General view of the apparatus for identifying the combustion line of a cigarette Fig. 2 Block writing diagram of the electronic circuitry for the apparatus as shown in Fig. 1 Fig. 3 Perspective view of the two SSA units Fig~ 4 Graphs showing the output signals from the two SSA units without phase shift Fig. 5 The non-rectified diffe.rence signal from the two and 6 SSA units where the degree of reflectance is the same at the two points scanned Fig~ 7 The difference signal at the poin~ where the combustion llne is identified Fig. 8 Time curve for the voltage U as the combustion line passes in front oE the stationary SSA units Fig. 9 ~raph representing the fluctuations .in the voltage Um and the limiting values (-to be explained subsequently) Fig. 10 Graph representing the movement of the combustion line of a cigarette during smoking Figure 1 shows the general design of an apparatus for identifying the combustion line of a cigarette. The cigarette consists of an incandescent zone ~13, the paper combustion line which is to be monitored ~2), the cigarette strand ~3) and a filter (4), which is clamped into a standard holder (5). The holder (53 is inserted into a smoking machine (6~, which can be programmed to "smoke" the cigarette according to a pattern that simulates the behaviour of a human smokerO
Parallel to the cigarette is a toothed rack (93, on which is mounted a sliding head carrying two SSA units (RL 1, RL 2) positioned side by side. The rack ~33 can be rotated by means of an electric motox (113, thus causing the two SSA units (RL 1, RL 2) to move parallel with the ciyarette. A displacement transducer (10~
--' lC -is connected either to the motor (11) or to the rack (9). The output signal of the displacement transducer (10) is proportional to the rotation of the rack (9~/electric motor (11~ and thus to the position of the SSA units ~RL 1, RL 2).
The output signals from the two SSA units, i.e.
the received signals, are fed in-to an analyzing device 112), which controls the motor via a control unit ~13~ and receives the signal from the displacement transducer (10). The analyzing device (12) is connected to a recording device (14~ n Figure 3 shows a perspective view of the two SSA units ~RL 1, RL 2), each of whi.ch contains a light-emitting diode operating at infrared frequencies as a t.ransmitter, and a suitable phototransistor (F~) which receives the light reflected from the surface of the cigarette. In order to ensure that ~he points scanned by the two SSA units (RI. 1, RL 2) are as close together as possible, an adjusting wedge (35) is posi-tioned between the two units (R~ 1, RL 2) in such a way that it maintains the units (RL 1, RL 2) at a predetermined angle to each other. This angle is 13 in the cas~ of the apparatus described.
' 1 1 ~
The two SSA units (RL 1 and ~L 2) are mounted toyether on the toothed rack ~9) by means of an attachment and can be made to move parallel with the ciyarette.
If only one SSA unit were to be used, any varia~ion in the distance between this single unit and the cigare-tte would result in a corxesponding change in the received signal. In order to minimize this effect, the apparatus described utilizes two SSA units (RL 1, ~L 2) so that any variations in distance can be almost completely offset by computing the difference between the two signals (E1 and E2) received by the two units.
As can be seen from Figure 2, the two SSA units (RL 1 RL 2~ are ed from a constank voltage source 515) which supplies a DC voltage (U1) and from a generator ~163 which supplies a ~inusoidal AC voltage. Th~
sinusoidal AC voltage from the generator (16~ and the DC voltage tU1) are fed into the first subtracter 517 so that the LEDs (transmitters) of the kwo SSA units (RL 1f RL 2) are driven by a sinusoidal AC voltage which is shifted upwards by the DC voltage U1.
7~
, The output of the subtrac~er t17) is linked to a junction (18), which is connected directly to the first SSA unit (RL 1) and via an all-pass network 519) to the second SSA unit (RL 2~. This all-pass network compensates for -the phase shifts between the two received signals caused by fluc~uations in the performance of the two units. Figure 4 shows the phase shift between the two received signals which occurs when the transmitters of the two SSA units (RL 1I RL 2) are powered directly by the supply voltage, The difference between these two signals - even if the degree of reflec-tance at the two points scanned is the same ~ would be sufficient to genera~e a relatively high output voltage r thus resulting in a faulty reading.
For this reason the phase shift must be offset by means of the all-pass network (19).
The light emitted from the LEDs (transmitters) is reflected from the surface of the cigarette and picked up by the phototransistors, which generate an output signal in proportion to the degree of reflectance at the surface of the cigarette. The output signals from the phototransistors are then fed into two high-pass filters ~20 and 21), thus isolating the alternating components of the received signals E1 and E2. These signals are then converted.
7t~3~
By feeding the two transmitters wi~h the sinusoidal AC voltage which is shifted upwards by the DC supply voltage U1~ it is possible to distinguish between the reflected infraxed light and the infrared emission from the incandescent zone, which con-tinuously irradiates the two receiversO
The outpu~ signals from the two high-pass filters ~20 and 21) - i.e. the alternating components of the signals received by the two 5SA units ~RL 1 and ~L 2) -are fed into a second subtracter (22~, which produces the difference between the two output signals. This difference is then amplified by means of an amplifier (23) and fed into a rectifier (24), the output signal from which represents the actual voltage IUm3, i.e. a voltage which is in proportion to the difference in the degree of reflectance ( ~3 at the points scanned by the two SSA units ~RL 1, RL 2)o Figures 5 and 6 show the two received signals E1 and E2, i.e~ ~he output signals from the two SS~ units (RL 1 and RL 2). In Figure 5 the two signals are shown in phase, while in Figure 6 they are in phase oppostion.
Figures S and 6 also show the non-rectified difference signal, i.e. the difference between the two received singals E1 and E2 when the degree of reflectance (~
is the same at the two points scanned.
Figure 7 shows the non-rectifled difference signal for the two received signals (E1 and E2) in phase opposition when the combustion line is identifiedO
This signal is the result of the difference in the degree of reflectance of the ash and that of the unburnt paperO
The difference signals sho~n in Figures 5 to 7 are thus generated at the output of the second subtracter (22).
After rectification in the rectifier (24), the voltage Um can be registered by a meter. Figure 8 shows the curve for the voltage Um as the paper combustion line passes in front of the two stationary SSA units (RL 1 and ~L 2). The graph shows an obvi~us peak which marks the transition between the two reflecting zones, i.e. the ash and the surface of the paper. As explained above, this sudden transition is due to the different degrees of reflectance (3 3 at the two points scanned.
If the two points scanned by the two SSA units (RL 1 and RL 2] are both located on the ash or the paper surface~ the difference signal will fall to zero, or approximately zero, as is shown in Figures 5 and 6 together with Figure 8. Figure 8 also shows a number t~J~ r ~
of levels (1L, 2L, 1H, 2H) on either side o~ the peak value for UmO These levels are selected at random on the sole condition that they lie above the apparatus noise threshold.
The output signal from the rectifier (24), i~eO the voltage Um, is applied via two junctions ~25 and 27 to two Schmitt triggers (26 and 28). One of these Schmitt triggers (26) is linked via a junction (29) to a third subtracter (31). With the aid of a voltage source U2 (32) the speed of forward and reverse movement can be varied. The output signal from the subtracter (31) is applied via an amplifier (33) to the motor 111). The Schmitt trigger (26) :is controlled when the rectified difference between the signals E1 and E2 received by the two 5S~ units (RL 1 and RL 2l - iOe.
the voltage Um - is less than 2L and greater than 2H
(see figures 8 and 9), thus causing the motor (11) to move the two SSA units (RL 1 and RL 2) back and forth in such a way that the voltage (Um) always remains within the range defined ~y these two extreme values. Figure 9 shows the corresponding switch-over points t2L and t2H~
which are dependent on the output voltage Ux2 from the Schmitt trigger ~26~.
7(~5i The constant rotation and counter-ro~a~ion of th~
motor (11) ~ which effects a corresponding back-and-forth movement of the two SSA units (RL 1 and RL 2~ -provides a sufficientl.y large number of readings for accurate evaluation and analysis.
During the puff phase, i.e. while the smoking machine (6) is in operation, the infrared emission from the incandescent zone (1~ is so powerful that the phototransistor (FT) of the SSA unit closest to that zone exceeds saturation point and therefore ceases to deliver a measurable signal.
By means of a time switch (not shown) the motor ( 11 ) is then triggered by the smoking machine in such a way that it causes the two SSA units (RL 1 and RL 2) to move slightly faster during the puff phase than the actual speed of advance of the combustion line.
In Figure 2 this adaptation is indicated by a transducer l34~, which is linked both to the third subtracter (31) and to the smoking machine (6) 7 This transducer (34) serves to trigger the mo-tor (11) via the smoking machine (6) during the puff phases~
7~5 Immediately following the end of a puff phase the infrared emission from the incandescent zone falls to a level where the combustion line (2) -with which the SSA units are still aligned -can once again be detected.
The two SSA units are displaced via the too-thed rack (9j (indicated in the diagram by a dotted line) by the motor (11), which is controlled accordingly by the voltage Um and the Schmitt trigger (26).
Either the rotation of the motor (11) or the position of the rack ~9) therefore serves to indicate the position of the two SSA units (RL 1, RL 2). For this purpose a displacement transducer (10) - e.gO a potentiometer connected to a reference vol-tage supply -is coupled to the motor (11) or to the rack (9).
This potentiometer delivers an output voltage which is in proportion to the position of the two SSA units iRL 1 and RL 2)o The output voltage is registered by a recording device (14) (e.g. an x-t recorder3, thus providing a direct indication of the rate of advance of the paper combustion lineO
As explained above, the Schmitt trigger 126) switches between the two values 2L and 2H (see Figure 8)o The second Schmitt trigger (28), which receives the ~'7~S
voltage Um via the junction (27~, swi.tches between the values 1L and 1H 5see Figure 8), so that the two Schmitt triggers (26 and 28~ generate the corresponding output voltages U 1 and U 2~ These two output voltages Uxl and Ux2 are then fed into a logic unit (30), either directly via the second Schmitt trigger (28), or indirectly via the first Schmitt trigger (26) and the junction (291, The logic unit (30) combines the two output signals x1 and x2 in accordance with the following logical function:
Y ~ X2 The output signal y from the logic unit (30~ is then fed to the pen lift connection o the x-t recorder (14).
The logic combination of the two output signals as described makes it possible to present the curve as a series of separate points due to the fact that the pen of the x~t recorder (14~ only traces the curve when the two SSA units (RL 1 and RL 2) are located between the two limiting values 1L and 2L and are moving towards 2Lo The corresponding switch-over points t1L and t1~ which are dependent on the output voltage Ux1 from the second Schmitt trigger, are indicated .in F:igure 9.
7~
~ 19 -Finally, Fig. 10 shows the movement of the combustion line of a cigarette, as recorded by the two SSA units (RL 1 and RL 2) moving parallel with the incandescent zone. The breaks in the curve caused by the lifting of the pen can be clearly seen.
Claims (14)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. Apparatus for opto-electronic identification of the combustion line of the wrapper encasing a smokable article (in particular the combustion line of cigarette paper, wrapper leaf or synthetic wrapper) which incor-porates two source and sensor assembly units (herein-after SSA units) positioned side by side for moving in the direction of travel of the combustion line (2) for reflective sensing applications (RL 1, RL 2), a subtracter (22) for the output signals from the sensors (FT) of the two SSA units, and a device (12) for detecting a sudden difference in the output signals from the SSA units (RL 1, RL 2) at the point of transition from ash (1) to wrapper at the combustion line (2).
2. An apparatus as set forth in Claim 1 which comprises a constant voltage source (15) for the gener-ation of a DC supply voltage (U1) to the SSA units (RL 1, RL 2).
3. An apparatus as set forth in Claim 2 which comprises a generator (16) for the supply of a sinusoidal AC voltage and a second subtracter (17) into which the output signal from the generator (16) and the DC supply voltage (U1) are fed, the output of the subtracter being fed to the SSA units.
4. An apparatus as set forth in Claim 3 in which an all-pass network (19) is incorporated between the second subtracter (17) and one of the two SSA units (RL 2).
5. An apparatus as set forth in one of Claims 1 to 3 in which the sensor (FT) of each SSA unit (RL 1, 2) is connected to a high-pass filter (20, 21).
6. An apparatus as set forth in Claim 1 which comprises a rectifier (24) for detecting the output signal from the subtracter (22) for the output sig-nals from the sensors and a meter connected to the rectifier (24) which measures the output voltage (Um) from the rectifier (24).
7. An apparatus as set forth in Claim 1 in which a follow-up control system (10, 11, 12, 13) moves the SSA
units (RL 1, RL 2) in accordance with the forward move-ment of the combustion line (2).
units (RL 1, RL 2) in accordance with the forward move-ment of the combustion line (2).
8. An apparatus as set forth in Claim 6 in which a follow-up control system (10, 11, 12, 13) moves the SSA
units (RL 1, RL 2) in accordance with the forward move-ment of the combustion line (2).
units (RL 1, RL 2) in accordance with the forward move-ment of the combustion line (2).
9. An apparatus as set forth in Claim 8 in which a motor (11) controlled by the output voltage (Um) from the rectifier (24) moves the SSA units (RL 1, RL 2) back and forth in the vicinity of the combustion line (2).
10. An apparatus as set forth in Claim 9 which incorporates a pen operated recording device, two Schmitt triggers (26, 28) connected to the output of the recti-fier (24), a logic unit for the output signals from the two Schmitt triggers 126, 28) and a pen-lift connector connected to, the output of the logic unit for the pen of the recording device (14).
11. An apparatus as set forth in Claim 10 which incorporates a voltage source (32) for generating the supply voltage (U2) to the motor (11) and a subtracter (31) connected to the voltage source (32) and to one of the Schmitt triggers (26).
12. An apparatus as set forth in Claim 10 or 11 which incorporates a displacement/voltage converter (10) connected to the motor and whose output is linked to the recording device (14).
13. An apparatus as set forth in Claim 9 for a smokable article placed in a smoking machine in which the motor (11) causes the SSA units (RL 1, RL 2) to travel at a higher speed during the puff phase of the smoking machine than during the intervals between puffs.
14. An apparatus as set forth in Claim 11 for a smokable article placed in a smoking machine in which the motor (11) causes the SSA units (RL 1, RL 2) to travel at a higher speed during the puff phase of the smoking machine than during the intervals between puffs, and in which a transducer (34) controlled by the smoking machine (6) is connected to a further input of the sub-tracter (31) connected to the voltage source for gener-ating the supply voltage to the motor and to one of the Schmitt triggers.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DEP3144189.0-52 | 1981-11-06 | ||
| DE3144189A DE3144189C1 (en) | 1981-11-06 | 1981-11-06 | Method for detecting the focal line of the wrapping of a smokable article and device for carrying out such a method |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1197705A true CA1197705A (en) | 1985-12-10 |
Family
ID=6145826
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000415015A Expired CA1197705A (en) | 1981-11-06 | 1982-11-05 | Procedure for opto-electronic identification of the combustion line of the wrapper encasing a smokable article, and apparatus for carrying out this procedure |
Country Status (5)
| Country | Link |
|---|---|
| CA (1) | CA1197705A (en) |
| CH (1) | CH660793A5 (en) |
| DE (1) | DE3144189C1 (en) |
| FR (1) | FR2515935B1 (en) |
| GB (1) | GB2111675B (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109068721A (en) * | 2016-02-17 | 2018-12-21 | 柏格瓦尔特Kc有限责任公司 | The method of smoking machine and grass product of smoking |
Families Citing this family (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FI68185C (en) * | 1983-03-01 | 1985-08-12 | Waertsilae Oy Ab | FOERFARANDE OCH ANORDNING FOER LAEGESOBSERVERING |
| IT1171723B (en) * | 1983-10-06 | 1987-06-10 | Sernagiotto Off Mec | AUTOMATIC CONTROL EQUIPMENT FOR THE SEDIMENTATION OF SLUDGE PRESENT IN THE SEWAGE SEWAGE |
| DE19749844C2 (en) * | 1997-11-11 | 2001-10-18 | Bat Cigarettenfab Gmbh | Length measuring device and method for cigarettes |
| CN103487549B (en) * | 2013-10-13 | 2015-03-04 | 中国烟草总公司郑州烟草研究院 | Method for evaluating and testing ignition tendency of cigarette |
| CN110596192B (en) * | 2019-09-22 | 2021-11-23 | 安徽上造智能设备科技有限公司 | Cable aging infrared detection device and use method thereof |
| CN111426794B (en) * | 2020-04-26 | 2022-07-01 | 云南中烟工业有限责任公司 | Method for representing cigarette combustion carbon line quality based on whole process of human body cigarette smoking simulation and whole visual measurement |
Family Cites Families (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB727403A (en) * | 1951-09-14 | 1955-03-30 | Wool Ind Res Association | Apparatus for reproducing with considerable mechanical power the movement of a beam of light |
| US4184080A (en) * | 1977-06-30 | 1980-01-15 | Molins Machine Company, Inc. | Ratiometric edge detector system |
| DE2814843C2 (en) * | 1978-04-06 | 1980-05-29 | Draegerwerk Ag, 2400 Luebeck | Gas measuring and warning device |
| DE2947249C2 (en) * | 1979-11-23 | 1981-11-12 | B.A.T. Cigaretten-Fabriken Gmbh, 2000 Hamburg | Method for determining the burning and / or smoldering speed of a smokable article and device for carrying out such a method |
-
1981
- 1981-11-06 DE DE3144189A patent/DE3144189C1/en not_active Expired
-
1982
- 1982-11-04 FR FR8218488A patent/FR2515935B1/en not_active Expired
- 1982-11-04 CH CH6425/82A patent/CH660793A5/en not_active IP Right Cessation
- 1982-11-05 CA CA000415015A patent/CA1197705A/en not_active Expired
- 1982-11-05 GB GB08231687A patent/GB2111675B/en not_active Expired
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109068721A (en) * | 2016-02-17 | 2018-12-21 | 柏格瓦尔特Kc有限责任公司 | The method of smoking machine and grass product of smoking |
| CN109068721B (en) * | 2016-02-17 | 2022-07-05 | 柏格瓦尔特Kc有限责任公司 | Smoking machine and method of smoking a tobacco product |
Also Published As
| Publication number | Publication date |
|---|---|
| DE3144189C1 (en) | 1983-05-19 |
| GB2111675A (en) | 1983-07-06 |
| FR2515935A1 (en) | 1983-05-13 |
| FR2515935B1 (en) | 1987-04-03 |
| GB2111675B (en) | 1985-12-04 |
| CH660793A5 (en) | 1987-06-15 |
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