SMOKING MACHINE DESIGN AND YIELD ERRORS UNDER
INTENSE SMOKE REGIMES . PART 1: THE INFLUENCE OF DEAD
VOLUME ON YIELD.
I.F.Tindall1, Cerulean, Rockingham Drive, Milton Keynes, UK
L.Crumpler, Cerulean, Richmond VA, USA
T.Mason Cerulean, Rockingham Drive, Milton Keynes, UK
Abstract
The difference in key analyte yields between smoking machine employing the rotary
and linear methods has long been tolerated on the basis that these are small under
the ISO regime and within the limits of expected experimental variance. These
differences are magnified under Canadian Intense conditions and give rise to
concerns that machines using the rotary principle for smoking have low NFDPM,
water and TPM yields.
The influence of the essential difference in design of a remote capture pad has been
investigated by eliminating other machine differences and “mimicking” the behaviour
of the two different machine types on a single machine. Careful deconstruction of the
smoke path has shown that the “dead volume” in a rotary system is both greater than
a linear system and significant in determining the apparent yield. Moreover this effect
is exacerbated by using the HCI regime through a change in the smoke matrix
formed. The relationship between regime conditions and dead volume has been
investigated and an empirical relationship derived.
The relationship between puff volume and vapour desorption is identified as a
secondary mechanism for lowering yields and is the subject of a separate paper.
The hazards inherent in using a remote capture pad and the consequences for HCI
smoking are made clear. Recommendations for design changes that minimise the
apparent lowering of yields are presented.
1
Author to whom correspondence should be addressed
1|Page
Introduction
A debate as to which smoking regime is most appropriate for routine analytical
smoking has existed for some time. WG9 of ISOTC126 investigated alternate
regimes and opened up the debate as to what is the most “representative” regime for
a human smoker and the nature of design features such as tip ventilation.
Discussions on selection of an appropriate intense smoking regime to complement
the ISO smoking regime have continued within ISOTC126 and while it appears that
the majority of members lean toward a regime based on Health Canada method T115 [1], absolute consensus has not yet been reached.
As part of the preparation for this potential additional method, a working group within
ISOTC126 was set up that examined the suitability of the method. During the
analysis of the data from this study it was noted that there were statistically
significant differences for the yields of some components between rotary and linear
smoking machines. This observation was confirmed by a CORESTA RAC study that
investigated the replacement of the CM6 monitor cigarette with the CM7 monitor and
smoked both ISO and HCI (Health Canada Intense) regimes [2].
Previously a CORESTA task force had carried out an exercise to harmonise the
yields of the two types of machines by controlling air flows for the two machines
under ISO conditions. Six brands of commercial cigarettes were used, chosen to
span the range 1 mg to 16 mg in a roughly logarithmic scale, as well as a monitor
test piece [3]. From this study estimates for repeatability and reproducibility for
NFDPM, nicotine and water were made available for the first time and the study
concluded that for all practical purposes there were no differences between smoking
machine types, CO yields were not considered.
In 1999 however, in anticipation of implementation of CO ceilings within the
European Union, differences observed in CO yields between the linear and rotary
machine types became a concern and a new CORESTA sub-committee was formed
to investigate these differences [4]. Coincidentally in 1995 a new automated rotary
smoking machine was introduced to the market which appeared to magnify
differences observed between linear and rotary machines for CO yields. A change in
the footprint of the rotary smoking machine to accommodate the automation was
discovered to have an impact on the air flow patterns within the smoking machine,
resulting in higher CO yields [5]. It is worth noting that the change in smoking
machine design relocated the 92mm CFH to a position remote from the smoking
port. The introduction of a modification kit and air-flow straightener on the affected
rotary machines brought the CO yields into acceptable if not perfect agreement with
linear machines and the older rotary design without affecting the other component
yields under ISO smoking conditions.
ISO smoking is characterised by taking 35mL puffs of 2 second duration every 60
seconds, whilst HCI smoking is characterised by 55ml puffs of 2 second duration
every 30 seconds with 100% of the ventilation holes blocked by means of adhesive
2|Page
tape. The air flow, lighting cycles and puff shape are common for the two regimes.
From these studies intensive smoking appears to amplify the differences in the two
machine types as can be seen from table 1[6]
3|Page
Table 1: Comparison of difference in yields for machine types in absolute terms and as a percentage of
the mean for all types.
CO
TPM
NFPDM
Water
Nicotine
Puff count
ISO Linear - Rotary
Absolute % of mean
mg/cig
-0.56
-3.9%
0.60
3.4%
1.00
7.0%
-0.49
-26.0%
0.06
4.6%
0.31
3.4%
HCI Linear - Rotary
Absolute % of mean
mg/cig
-0.73
-2.7%
5.47
12.8%
2.62
9.0%
2.76
25.6
0.12
4.4%
0.22
1.8%
Increase in
% ISO to
HCI
1.2%
9.5%
2.0%
51.5%
-0.2%
-1.5%
There was noted a greater variability in linear machine results but as these can in
part be a consequence of “averaging” of the rotary method where fewer
measurements are required these, in part, are of lesser significance. What may be
considered significant is the offset between the machines, rotary machines giving
lower NFDPM, TPM and water yields. This is of particular note where there are
legislative ceilings for NFDPM.
There are fundamental differences between the two machine types. There are also a
number of detailed differences between commercially available machines but these
are a consequence of the design solutions selected and are not in any way
fundamental to the design concept.
The fundamental differences are twofold. Firstly the capture pad on a rotary machine
is located remotely from the smoking article whilst on a linear machine the smoking
article is immediately adjacent to the capture pad. This distance between pad and
rod in a rotary machine is dependent upon the exact design parameters chosen.
Secondly in a rotary machine the puff engine (or syringe) is shared for all smoked
ports whilst in a linear machine each port has its own puff engine.
4|Page
B
A
B
F
E*
E
C
C
KEY
D
D
A= Cigarette
B= Lip seal
C= Neoprene washer
D= Puff engine
E= Cambridge filter pad holder
F= Dead volume (rotary only)
G = connector to puff engine
G
Rotary Smoking
machine arrangement
Linear Smoking
machine arrangement
A
A
E*
D
D
E
Figure 1: schematic representation of linear and rotary smoking machines - note similarities in design
It is possible that these two fundamental design features of the competing machine
types underpin the differences observed during these studies and a better
understanding of the causes of such discrepancies would lead to a common platform
for cigarette comparisons and rankings under the two methods ISO and HCI
5|Page
Experimental
In order to eliminate as many experimental artefacts as possible, and to examine
only the fundamental machine type differences outlined above, two experimental
constructions were devised.
In the first a rotary smoking machine was configured such that it could smoke in the
normal rotary manner and simultaneously “mimic” the behaviour of a linear machine
as far as puff capture and through pad flow was concerned. In the standard
arrangement a 92mm pad was located remotely from the cigarette. In the alternate
arrangement a series of 10 44 mm Cambridge filter pad holders were situated
around the smoking ring. The ring is still rotated with the cigarette following the same
path as it would in conventional rotary smoking where a 92mm pad is used.
In the second test apparatus a linear machine was configured such that the capture
pad could be immediately behind the cigarette as in a standard linear smoking
machine or remote located as in a rotary smoking machine.
In these arrangements confounding factors such as air flow, cigarette position,
lighting conditions and so on could be eliminated from study as each was held
constant for a pair of comparisons. Furthermore the construction of the individual
parts of the machine could be removed and weighed to ascertain where any
deposition of condensate could take place.
A schematic of the two systems is shown. As can be seen a CFH can be placed
immediately behind the cigarette (throughout the following paper this is described as
the “44mm holder”) or can be placed remotely either alone or in series with the
44mm holder (this CFH is referred to as the “92mm holder” throughout). In the case
where this is in series with the 44mm holder then this is used to trap condensate that
has escaped from the 44mm holder.
6|Page
Figure 2: schematic of arrangement used for experimentation
A series of experiments were conducted as shown in table 2:
Table 2: Table of experiments performed to establish relationship of dead volume and dead time to
differences between linear and rotary smoking machines.
Objective
1.Confirm that observed
differences between
machine types are a
consequence of machine
design and not of smoking
conditions
Experiment
Under both ISO and HCI
conditions smoke into 44mm
holder and 92mm holder on
both machine types
comparing TPM, puff and CO
levels.
2. Identify sites for
deposition of condensate
within smoking machines
Smoke under both ISO and
HCI on both machine types
and dismantle smoking
machine as far as the puff
engines determining the TPM
deposited at each point within
the smoking machine
Potential outcomes
IF differences are not combustion
related then CO concentrations
should be consistent for 44mm and
92mm holders AND between
machine types. ALSO under HCI
44mm holder TPM > 92mm holder
yields and in line with CORESTA
study for similar products.
IF TPM is found in greater
quantities before the capture pad
for a 92mm holder under HCI
compared with a 44mm holder
then the capture dead volume is
significant.
IF TPM found between cigarette
and 92mm holder capture pad is
more significant under HCI than in
ISO smoking then there are
significant differences in the smoke
matrix under the two regimes that
intensity condensation
7|Page
3. Establish the relationship
between distance to capture
pad from butt in terms of
condensate deposition.
4. Establish the relationship
between puff interval and
condensate forming
between butt and capture
pad
Extend distance between butt
and capture pad (keeping
cross section area and
materials constant) and
weigh TPM as a function of
capture distance.
On a modified linear machine
with 92mm holder, keeping
puff volume constant
increase the puff interval and
determine the levels of TPM
deposition between butt and
capture pad as a function of
dead time.
IF TPM is found in significant
quantities after the capture pad
then desorption of semi volatile
components are taking place and
this will contribute to the observed
differences in TPM and NFDPM.
IF losses increase with distance
between butt and capture then
dead volume is a significant factor
in the difference between machine
types.
IF there is a time based
phenomenon then as dead time
increases then deposition should
increase. IF deposition is near
instant deposition sites (nucleation
sites for the smoke matrix) may be
significant.
All experiments were conducted using CORESTA monitor #6 test pieces conditioned
together with capture pads under ISO conditions. Smoking experiments were
conducted with ISO air flows. Although ISO temperature and humidity conditions
could not be guaranteed these were approximately adhered to.
HCI smoking was conducted for 55mL puffs of 2 second duration, 30 second interval
on unventilated products without tape as there is some indication that taping can
change yield results even on unventilated products. Three replicates per smoke run
were smoked. No clearing puffs were taken.
For ISO smoking 35mL puffs were taken of 2 second duration at 60 second intervals.
Five sub runs were smoked for each smoke run. No clearing puffs were taken.
8|Page
Results
Experiment 1
ISO and HCI smoking was conducted on both a rotary machine and linear machine
with pads in the 44mm position (5 and three 3 per pad for the two regimes
respectively) and with a pad in the normal rotary position (20 and 10 rods per pad
respectively). The difference in yields for TPM and CO between the two pad
locations is shown in table 3, this is compared with the prior CORESTA study. As
can be seen broadly similar results are obtained with this arrangement allowing us to
conclude that the smoking conditions within the machine types are not responsible
for the yield differences observed in the CORESTA study but are in fact a result of
the two fundamental design differences in the machine types – the position of the
pad location and air flow through the pad.
Table 3: Comparison of yields with pad locations at 44mm and 92mm locations for the two machine types
linear and rotary.
TPM
CO
ISO
difference
CORESTA
(linear rotary
0.60mg
-0.37mg
ISO
difference
44 – 92 on
rotary
ISO
HCI
difference difference
44-93 on CORESTA
Linear
HCI
difference
44 – 92
on rotary
ISO
difference
44-93 on
Linear
0.40mg
-0.35mg
0.77mg
-0.06mg
5.68mg
0.41mg
4.15mg
0.32mg
5.47mg
0.73mg
Experiment 2
In this experiment two regimes (HCI and ISO) were smoked on the rotary smoking
machine in 92mm pad and 44mm pad mode. In each case components of the
smoking machine between cigarette and puff engine were removed and carefully
weighed before and after smoking to establish where, if anywhere, in the system
condensate deposits. These weight changes were normalised to per cigarette
measurements and a mass balance conducted to establish if the two pad types had
the same overall yields for TPM.
9|Page
Table 4 shows the measurements made for the different regimes and experimental
set ups.
Table 4: Comparison of components from smoking ISO and HCI regimes on a rotary machine fitted with
44mm and 92mm pads. Component Key: C = neoprene washer, E* = 44mm CFH, F= path from test piece
to 92mm holder, E= 92mm CFH, G= path from 92mm holder to CFH
Fig 1 reference
C
HCI smoking (mg/tp) TPM
yield
92mm pad
44mm pad
0.50
C+E*
ISO smoking (mg/tp) TPM
Yield
92mm pad
44mm pad
0.2
42.30
17.10
F
5.67
0.28
1.16
0.0
E
36.61
0.63
16.71
0.19
G
0.46
0.40
0.26
0.01
Total mass
balance
43.24
44.13
18.13
17.30
It can first be seen that there is a near mass balance between the 44mm and 92mm
pad smoking in both regimes with only a 2% difference in HCI and a 4% difference in
ISO. This indicates that, as expected, using the alternate pad capture system does
not affect the combustion/pyrolysis of the cigarette and the TPM generated is the
same. Moreover it indicates that the TPM can be tracked through the system.
It is of note that considerable TPM is captured by the neoprene washer. In most
cases on a linear machine the washer would be included with the CFH for TPM
determination but not considered when determining nicotine and water. In this way
the washer TPM is considered entirely as NFDPM by the nature of the calculations
made. In the rotary system this washer is never considered as TPM or NFDPM and
is a loss to the system and adds to any offset in TPM, nicotine and water observed
between the machine types. This accounts for approximately 0.5mg when HCI
smoking on this test piece and 0.2mg when considering ISO smoking.
A second observation is that there is considerable TPM deposited in the path
between the smoked article and 92 mmpad in conventional rotary smoking – part F
in figure 1. This accounts for 5.67mg per cigarette in this experiment. This will be a
mixture of NFDPM, water and nicotine. On the face of it this would account for the
observed TPM offset between linear and rotary machines in TPM, however there are
other confounding factors which suggest that this is part of the difference and not all.
The proportion of “lost” TPM deposited in this path is different from HCI as compared
to ISO. In the HCI method this is 15% of the captured TPM fraction whilst for ISO
only 7%. It is clear that HCI smoking produces a smoke matrix that is more likely to
condense on the transfer tube than ISO and so “amplifies” the inherent losses in the
system to a more noticeable level or has some characteristic with the same
outcome.
10 | P a g e
A third observation is that after the 44mm capture pad there is condensate formed
on the walls of the transfer tube, captured by the 92mm secondary pad and even
some condensate after this secondary pad. The clear implication is that this is
material that has either passed through the 44mm CF pad without being trapped and
then condensed on the walls of the transfer tube or it is material that has been
initially trapped and then desorbed from the filter pad holder to deposit further down
the machine. Consideration surrounding this condensate after the 44mm pad is the
subject of a separate paper [7].
Experiment 3
On a linear machine it is possible to simply change the distance between the smoke
article and capture pad (keeping the article in the same location within the smoke
hood). It is also possible to simply change the inter-puff interval and puff volume. An
experimental arrangement based on a linear smoking machine was used to
determine how the dead volume characteristics influence the degree of deposition
taking place before the capture pad. Total TPM was calculated by weighing TPM
deposited in the CFH, the washer and labyrinth seals, the eccentric connector and
any tubing between CFH and eccentric connector. TPM yields at the CFH are
expressed as a proportion of the total yield. Total yield, calculated through a mass
balance process, at each point has been compared with the total yield at “distance 0”
as a control to establish that the moving of the capture pad has not introduced any
experimental artefacts. Extending the path length between capture pad and test
piece has a profound effect upon the observed TPM for HCI smoking and a very
small effect under ISO smoking.– see table 5 and figure 3.
Table 5: ratio of TPM captured on the CFH to total TPM with respect to distance from the test piece butt.
ISO ratio CFH TPM to Total TPM
HCI ratio CFH TPM to total TPM
ISO ratio total TPM to TPM at
origin
HCI ratio total TPM to TPM at
origin
0
0.99
0.99
120
0.95
0.89
170
0.98
0.86
220
0.95
0.86
270
0.90
0.85
1.00
0.99
0.97
1.04
0.98
1.00
1.02
1.00
0.98
0.96
11 | P a g e
Proportionate TPM yield by distance from
test piece butt
1.1
Yield TPM relative to initial location %
1.05
1
0.95
0.9
0.85
Total yield ISO
R² = 0.9984
Total yield HCI
0.8
ISO CFH to total yield
0.75
0
50
100
150
200
250
300
Distance from test piece butt mm
Figure 3: Graph showing loss of TPM relative to total TPM generated with distance from the test piece
butt
In HCI smoking there is greater loss per mm distance for the first move of the pad
compared with subsequent moves. As a comparison the rotary machine used for
experiment 1 had its 92mm pad 160mm distant from the test piece butt and had a
proportionate loss (92mm pad TPM/total mass balance TPM) of 15% (c.f. above
14%). This can be considered excellent agreement for the two machine types and
the technique appears representative of the rotary smoking machine for comparison
purposes. It is possible to calculate the expected loss depending upon the distance
the capture pad is from the butt and this could be applied to the design of rotary
smoking machines.
By contrast there are only small losses under ISO smoking and the losses are
monotonic with distance from the test piece butt. It is of note that the total yield using
the mass balance calculation used throughout this paper remains fairly constant
independent of distance of the CFH from the test piece .
12 | P a g e
Experiment 4
The time that the smoke is held before entering the 92mm pad holder may also be
significant in the formation of condensate in a rotary (92mm pad) machine. It should
be understood that when a puff is taken on a rotary machine smoke is taken into the
machine and into the pad but at the end of the puff when the puff engine valve is
closed and the carousel moves some of the smoke is trapped between cigarette and
smoke ring. This should be pulled into the 92mm pad at the next puff, forming the
start of the next capture but this smoke is left in the dead volume for the length of the
inter-puff interval. Any condensation may happen immediately on smoke particles
impinging on the surfaces of the transfer tube or this may be a time based
phenomenon. Again using the linear machine fitted with a pad that could have an
adjustable dead volume an experiment was conducted where the time between puffs
was varied.
Figure 4 shows the proportionate loss for different puff volumes for changing interpuff frequency.
Ratio of TPM Deposited before CFH to total
TPM for remote CFM
25%
55ml puff
Percentage of TPM in transfer tube
35ml puff
Poly. (55ml puff)
20%
Linear (35ml puff)
15%
R² = 0.9519
10%
5%
0%
0
20
40
60
Interval between puffs seconds
80
100
Figure 4: Graph of changing ratio of TPM in transfer tube to total TPM (transfer tube plus CFH) for
increasing puff interval with constant puff volume.
13 | P a g e
The 55mL puff volume curve shows for puff intervals greater than 15 seconds
relatively constant ratios of deposition. This implies that the degree of deposition is
independent of puff interval and so this process of deposition is more likely to be an
immediate or instantaneous process rather than one driven by nucleation of particles
that precipitate out of the smoke matrix around suspended smoke particulates.
The 15 second interval results do not follow this pattern. There is evidence [8] that
higher pyrolysis temperatures result in higher water content of mainstream smoke
and higher pyrolysis temperatures can be achieved by reducing inter puff intervals.
The shorter interval between puffs will increase the non-puffing pyrolysis
temperature and consequently the water content of the smoke matrix. This will distort
the deposition ratios and so becomes non representative of the HCI smoking
process.
The 35mL puffs have lower ratios of deposited matter to total TPM than for the 55mL
puff. In this case the ratios are almost constant with the 15 second interval only
showing slightly greater levels of deposition.
It is clear however that the water in the smoke stream is instrumental in causing
deposition in the dead volume. The HCI greater water content is the underlying
reason for the more pronounced deposition effect which occurs near instantaneously
after the puff.
Discussion
Experiment 1 shows quite clearly that the combustion/pyrolysis conditions in the two
machine types are not leading to an offset in yields as in both cases where on a
single machine the CFH has been located in different places the 44mm pad option
gives a different TPM yield than the 92mm pad option and this difference is in line
with those found in collaborative studies.
The CO concentration per cigarette is always comparable between the two pad
positions indicating that the presence of the CFH is not important for this CO
analysis.
Furthermore it shows that the arrangement of 44mm pads around the periphery of a
rotary smoking machine mimics the behaviour of a linear machine and can be used
to simulate linear machine behaviour for comparison purposes. Similarly the remote
location of a 92mm pad on a linear smoking machine mimics the behaviour of a
normal rotary machine and can be used as such for comparison purposes.
Experiment 2 shows a number of effects. Firstly that it is evident that there are
losses in condensate in the rotary arrangement (92mm pad) before the pad capture.
These losses are proportionately, and absolutely, larger in the HCI smoking regime.
It is notable that if these losses were not present, yields in TPM would be near
equivalent between the two arrangements. Changing details of the design may
minimise such losses.
14 | P a g e
Smoking under the HCI regime highlights the inconsistencies that can be introduced
into a comparison method when two different machine types are being used. The
ISO method (ISO 4387 [9]) when applied to HCI has an inherent impact upon the
observed offset in yields and also the variability of measurement. Firstly the
neoprene washer is not included in the determination when a rotary machine is used
but this can under HCI conditions contain up to 0.5mg of TPM per cigarette. This is
included in TPM in the same experiment conducted on a linear or rotary smoking
machine with 44mm CFH. Furthermore this TPM, by the nature of the calculation,
would be considered to be entirely NFDPM as no extraction and measurement is
made of nicotine and water.
A second source of inconstancy is treatment of the CFH itself. Wiping of only the
front portion of the CFH ignores the contribution of any volatile condensate after the
filter pad itself as this is not analysed. Additionally the process of wiping the front of
the holder is approximately 30% to 70% efficient, any remaining condensate is
considered by the nature of the NFDPM calculation to be entirely NFDPM despite
containing nicotine and water. Under ISO smoking conditions this is a small error but
as the deposition on the front of the holder increases under HCI this error is
magnified. This source of error and the “wiping out” error could be removed with in
holder extraction but as yet this is not a viable or approved option for routine
analytical smoking [10].
Experiment 3 shows clearly that as the dead volume increases the degree of loss or
deposition increases for HCI but not significantly for ISO smoking. However this is
not the entire story. The puff intensity and inter puff interval also have an influence
on how much condensate reaches the 92mm pad. The more intense the puff, the
greater the deposition before the capture pad.
So is there something different about the smoke that makes it more likely that the
mean free path of the smoke is shorter in CI smoking? Figure 5 shows the relative
proportions of CO and water to NFDPM for the two smoking regimes. The greater
water and lower CO when normalised to NFDPM may indicate that there is
something different about the smoke formed under HCI. Proportionately lower CO
and higher water content may mean there is a more complete degree of combustion
achieved under intense conditions which would change both the chemical and
physical makeup of the smoke vapour / matrix. This difference, either chemical or
physical in origin, appears influential in the propensity of the smoke condensate not
to reach the pad.
15 | P a g e
difference % HCI yield normalised to NFDPM -%
ISO yield normalised to NFDPM
% change in yield normalised to NFDPM for
linear and rotary systems CM6
30
25
20
15
10
Linear
5
Rotary
0
-5
-10
NFPDM
Water
CO
Nicotine
TPM
Figure 5: Yield change between HCI and ISO smoking normalised to NFDPM for linear and rotary
machines. Note increase in water and decrease in CO. TPM increase follows increases in water.
Experiment 4 shows that the ratio of deposition in the transfer tube to that in the pad
is not puff interval time dependant. This suggests that the smoke deposits
immediately after puffing rather than droplets forming around nucleation sites such
as how raindrops form in a cloud. The increased water vapour in the smoke drives
this immediate deposition process, the larger puff volume causes more water to form
during pyrolysis/combustion probably due to the higher coal surface temperatures
[11].
16 | P a g e
Conclusions
There are some systematic errors with the ISO methodology when applied to HCI
smoking in the way that condensate is treated on the front of the holder, the
omission of the holder rear from extraction and analysis, and the omission of the
neoprene washer from the calculation. This in part accounts for some method
variability.
However we can say that although these effects are non-zero the majority of the
difference in TPM yield between the two pad locations is caused by the condensate
not reaching the pad and depositing in the transfer tube between test article and
92mm pad.
Locating the CFH further from the test article increases the observed degree of
deposition under HCI conditions but not significantly under ISO conditions.
Furthermore as the intensity of the puff increases (increasing volume) the
proportionate degree of deposition increases suggesting a fundamental difference in
the chemical or physical makeup of the smoke matrix as the puff intensity changes.
Changing the inter puff interval has only a small effect on the ratio of deposition in
the dead volume to that on the pad holding other dead volume conditions constant
and so it is concluded that the deposition is rapid and may occur as smoke passes
through the transfer tube and not primarily when held in the dead volume between
puffs.
It is clear that alternate smoking regimes may have unexpected consequences on
the TPM capture efficiency when using different smoking machine arrangements, the
linear machine with its immediate capture system probably being the most
consistent.
In practical terms for HCI smoking on a conventional rotary machine the large dead
volume between cigarette and capture pad causes a decrease in yield in TPM and
the components therein. This could be rectified in part by locating the pad closer to
the cigarette as in a linear smoking machine but this would lose much of the
functionality associated with automated rotary smoking.
The influence of condensate forming after the capture pad has not been considered
in this paper and is the subject of a separate study but it should be noted that this
also has an influence on the observed yield and may also have an influence on
impinger and other capture based experiments.
17 | P a g e
References
[1] Health Canada Test Method T-115 – Determination of Tar, Water, Nicotine and
Carbon Monoxide in Mainstream Tobacco Smoke, 1999-12-31.
[2] “2011 Collaborative study of CORESTA Monitors #6 (CM6) and #7 (CM7) for the
determination of test piece weight, TPM, water, Nicotine, NFDPM, Carbon monoxide
and puff count obtained under mainstream ‘ISO’ and ‘Intense’ smoking regimes”.
Thomas Verron, 2011
[3] CORESTA report 1991-1 “The determination of repeatability (r) and
Reproducibility (R) for the measurement of Nicotine dry particulate matter (NFDPM),
nicotine and water using CORESTA recommended methods 7,8,21,22,23 and 25”,
Task force for the review of smoking methods 1991.
[4] Official Journal of the European Communities, “DIRECTIVE 2001/37/EC OF THE
EUROPEAN PARLIAMENT AND OF THE COUNCIL of 5 June 2001 on the
approximation of the laws, regulations and administrative provisions of the Member
States concerning the manufacture, presentation and sale of tobacco products”
2001, L194 / 26.
[5] Thomsen, “Experiences with analytical smoking of cigarettes” CORESTA
Congress Kyoto 2004
[6] Data taken from RAC sub group technical report “2011 collaborative study of
CORESTA monitors #6 (CM6) and #7 (CM7) for the determination of test piece
weight, TPM, water, nicotine, NFPDM, carbon monoxide and puff count obtained
under mainstream ‘ISO’ and ‘intense’ smoking regimes”
[7] Tindall, Crumpler, Mason “Smoking machine design and yield errors under
intense smoke regimes. Part 2: The influence of puff volume on desorption of volatile
smoke components” CORESTA Congress Sapporo 2012
[8] Hendray, Laszlo, Beitrage zur Tabakforschung, 1974, 7, 276
[9] ISO 4387:2000: Cigarettes - Determination of total and nicotine-free dry
particulate matter using a routine analytical smoking machine
[10] Cote, Verreault ;“Overestimation of tar yields at Canadian intense smoking
regime: factors effecting accuracy” : CORESTA 2010 Edinburgh
[11] Baker, Kilburn, Beitrage zur Tabakforschung, 1973, 2, 79
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