4,459,103 Automatic volatile matter content analyzer

Patent Number/Link:

United States Patent [19]

Gieskieng

[11] Patent Number:

[45] Date of Patent:

4,459,103

JuI. 10, 1984

16 Claims, 4 Drawing Figures

4,223,549 9/1980 Kitzinger 374/142 X

4,330,808 5/1982 Sawada et aI. 73/28

4,358,948 1111982 Plessers 374/26

Primary Examiner-Daniel M. Yasich

An analyzer is provided for use in determining the volatile

matter content of coal and coke. The analyzer automatically

adjusts a position of a crucible containing a

coal or coke sample relative to a furnace depending

upon the temperature of the crucible. The crucible is

supported and the temperature of the crucible and sample

is sensed by means of a thermocouple arranged as a

sling for contacting the crucible. The sensed temperature

is compared with a predetermined and desired

temperature. A comparison difference triggers a vertical

movement of the crucible and sample, within the

temperature profile of the furnace, using a servomotor

until the crucible is positioned such that the sensed

temperature and desired temperature correspond.

[54] AUTOMATIC VOLATILE MATTER

CONTENT ANALYZER

[75] Inventor: David H. Gieskieng, Arvada, Colo.

[73] Assignee: Hazen Research, Inc., Golden, Colo.

[21] AppI. No.: 356,858

[22] Filed: Mar. 10, 1982

[51] Int. C1.3 C21D 11/00; F27B 9/40

[52] U.S. Ct•........................................ 432/43; 266/87;

373/136; 374/180; 432/45

[58] Field of Search 374/157, 139, 180, 26;

136/229,234,232,230; 164/154,449; 266/87;

432/43,45

[56] References Cited

U.S. PATENT DOCUMENTS

2,864,878 12/1958 Da1glish 136/229

3,444,740 5/1969 Davis 136/230 X

3,463,005 8/1969 Hance 374/157 X

3,598,386 8/1971 Murphy 266/87 X

3,653,262 4/1972 Ehrenfried et aI. 374/142

[57] ABSTRACT

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BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram of the present invention;

FIG. 2 is an enlarged, fragmentary, side elevational

view of the thermocouple sling supporting a crucible;

FIG. 3 is a bottom plan view of the thermocouple

sling without the crucible; and

FIG. 4 is a detailed schematic of the controlling/timing

circuit of the present invention.

provides a sensed temperature signal of itself and consequently

is indicative of the temperature of the crucible

it contacts and the sample contained therein. The movement

of the crucible in the vertical direction can be

5 made to be a function of the temperature sensed by the

thermocouple sling. The servomotor is controlled by a

controlling/timing circuit using the temperature signal.

More particularly, the thermocouple sling of the

present invention includes two dissimilar metals, in this

10 case Chromel and Alumel, to generate a sensed temperature

millivoltage signal relating to the temperature of

the thermocouple sling, crucible, and the sample. The

sensed temperature signal is inputted to the recorder

device which in addition to recording, outputs a voltage

somewhat proportional to the sensed temperature. The

temperature-related voltage provided by a recorder

retransmitting slidewire is compared with one or more

predetermined adjustable voltages chosen to correspond

to desired temperature levels or set-points. Any

difference between the sensed temperature and the target

temperatures is translated into movement of the

crucible to a different height within the furnace. Specifically,

if the thermocouple sling sensed temperature is

less than the target or set-point temperature, the servomotor

is activated to lower the crucible relative to the

furnace to expose it to higher heat. Conversely, if the

sensed temperature is greater than the predetermined

desired temperature, the servomotor is activated to

raise the crucible relative to the furnace. In such a manner,

the temperature to which the coal sample is subjected

can be controlled at one or more temperature

set-points for predetermined time periods to assure a

proper determination of volatile matter content.

In view of the foregoing, it is readily seen that a

number of advantages of the present invention are

achieved. An apparatus is provided for automatically

sensing and controlling the temperature of a coal sample

to determine its volatile matter content. More significant,

a thermocouple sling provides two important

functions. The thermocouple sling not only senses the

temperature to which the coal sample is being subjected

but also acts to support the crucible and coal sample

held by the crucible, providing a contact measurement

of the crucible temperature and hence the temperature

of the contained sample. In addition, this analyzer automatically

moves the vertical position of the crucible and

coal sample as a function of temperature, unlike previous

devices which rely solely on predetermined positions

in a furnace. Use of the present invention permits

rapid and accurate testing of volatile matter content of

a coal sample, since the reproducibility of test results is

maximized because of the increased precision in temperature

control and heating rates.

Additional advantages of the present invention will

become readily apparent from the following discussion

when taken in conjunction with the accompanying

drawings.

4,459,103

DISCLOSURE OF THE INVENTION

AUTOMATIC VOLATILE MATTER CONTENT

ANALYZER

In accordance with the present invention, an apparatus

is provided for use in analyzing the volatile matter 60

content of coal and coke. The apparatus includes a

loosely covered crucible for holding a small sample of

coal or coke. A thermocouple-sling combination is releasably

joined to the crucible for supporting the crucible.

The thermocouple sling is fastened to a motorized 65

suspension and wired to a recorder device. The crucible

is vertically movable within a tubular furnace by using

the servomotor. The thermocouple sling combination

An empirical distillation method analysis of the volatile

matter content of coal and coke samples is intended 15

to provide a measure of the volume of gaseous product,

exclusive of the free moisture content, which is produced

from such samples under a set ofstandard heating

conditions. The volatile matter content is a parameter

used in classifying coals and is significant in determining 20

and designing compatible combustion hardware for use

in the coal combustion process.

In the ASTM Standard Test Method for "Volatile

Matter In The Analysis Sample of Coal and Coke", D

3175-73 (1973), a method is disclosed for determining 25

the volatile matter content of coal or coke. The method

involves weighing the coal sample, heating the coal

sample to determine the weight loss after the heating,

determining the moisture content of the coal sample

using the standard found in ASTM D 3173, and then 30

subtracting the moisture content from the weight loss.

For the heating step, an operator determines, beforehand,

the approximate desired position of the coal sample

in a vertical tubular furnace by using a portable

thermocouple. The thermocouple is not connected to 35

the crucible but is, typically, a separate device inserted

by the operator into the furnace for use in determining

the temperature profile therein. In another known embodiment,

a thermocouple device is connected to the

furnace itself for providing an indication ofthe tempera- 40

ture thereof at that specific point in the furnace, usually

the bottom, so that this may be used to adjust approximately

the temperature of at least the hottest point of

the temperature profile.

An automatic volatile analyzer of coke and coal is 45

described in the EDP catalog with respect to the PreiserlMineco

volatile programmer. The analyzer described

includes holding timers for use in determining

when to move a crucible containing a coal sample to

different positions in a furnace. Different descent rates 50

of the crucible into the furnace area are also provided in

this automatic analyzer. This analyzer moves the crucible

as a function of time to preselected positions in the

furnace. Although these preselected positions in the

furnace are expected to be at desired temperatures, this 55

is often not the case.

FIELD OF THE INVENTION

The present invention relates to an apparatus for use

in determining the volatile matter content of coal and

coke and, in particular, is directed to a temperature

sensing and controlling arrangement, which also functions

to support a crucible in which the coal or coke is

placed for analysis.

BACKGROUND ART

4,459,103

DESCRIPTION OF THE PREFERRED

EMBODIMENTS

In accordance with the present invention, an apparatus

for use in empirically detemining the volatile matter 5

content of a coal or coke sample is provided. With

reference to FIGS. 1, 2, and 3, the apparatus includes a

crucible 10 having a slightly loose cover 12 for holding

or containing the sample of coal or coke. The crucible

10 is releasably supported by a thermocouple mecha- 10

nism in the form of a thermocouple sling 14. The thermocouple

sling 14 includes two dissimilar metal elements

16, 18. In the preferred embodiment, the two

metal elements are Alumel and Chromel. As can best be

seen in FIGS. 2 and 3, the two elements 16, 18 are 15

joined together to form thermocouple junctions 20, 22

using "Quiktip" connectors. The two thermocouple

junctions 20, 22 contact or touch the crucible 10 and are

used to sense the temperature of the crucible 10. It is

also appreciated that since the thermocouple junctions 20

20, 22 contact the crucible 10 containing the sample, the

thermocouple junctions 20, 22 also provide an indication

of the temperature of the sample. The sensed temperature

signals from the two thermocouple junctions

20, 22 are averaged to provide a single sensed tempera- 25

ture signal. Portions of the two elements 16, 18 are

formed in the shape of a semi-circle and connected

together at the thermocouple junctions 20, 22 to provide

an opening for receiving the crucible 10. The elements

16, 18 then extend upwardly to be electrically 30

connected to a recorder device 24 through a flexible

electrically insulated conductor 26 weighted on each

end by the masses of weights 28, 30. The recorder device

24 provides a visual indication· of the temperature

sensed by the thermocouple sling 14 as well as making 35

a pen recording on a strip chart.

From the recorder device 24, an electrical representation

of the sensed temperature signal is obtained from its

retransmitting slide wire and is applied to a controlling/

timing circuit 31 of FIG. 1. The controlling/timing 40

circuit 31 controls the energization or activation of a

servomotor circuit 33 according to preplanned setpoints

and periods of time. The servomotor circuit 33 is

operatively connected to a pulley 32 about which the

insulated conductor 26 is wrap hung. The insulated 45

flexible conductor 26 carries the sensed temperature

millivoltage signal to the recorder device 24. The servomotor

circuit 33 is used to turn or rotate the pulley 32

clockwise or counterclockwise for raising or lowering

thermocouple sling 14, crucible 10 and the sample con- 50

tained therein in a substantially vertical direction with

respect to a tubular furnace 36. The temperature of the

tubular furnace is initially regulated by a powerstat 38

and left set.

The furnace 36 has a temperature profile with the 55

hottest part located at he bottom thereof. Preferably,

one portion or level of the furnace 36 has a temperature

of 600' C. and another lower level or portion of the

furnace 36 has a temperature of 950' C. It has been

found that an accurate determination of volatile matter 60

content of coal and coke can be made when a sample

thereof is subjected to heat at these two different temperatures

for preselected time periods.

Referring now also to FIG. 4, as well as FIG. 1, a

more detailed representation of an embodiment of the 65

present invention is shown. The controlling/timing

circuit 31 of FIG. 1 includes reference circuit 40. The

reference circuit 40 includes a first variable resistor 42

which includes a sliding contactor 44 positioned at a

predetermined position along the resistor 42 so that a

first reference temperature signal voltage corresponding

to a first predetermined and desired temperature is

picked off and applied to a comparator circuit 46. The

reference circuit 40 also includes a relay 48 for switching

between the first reference temperature signal and a

second predetermined reference signal, which is provided

by means of a second variable resistor 50 having

a sliding contactor 52. The reference circuit also includes

a relay 54 for removing the excitation of variable

resistor 50 at a later preselected time. In the preferred

embodiment, the first reference temperature signal corresponds

to a temperature of 600' C. and the second

reference temperature signal corresponds to a temperature

of 950' C.

The comparator circuit 46 also receives a retransmitted

temperature related signal from the recorder device

24, which is basically responsive to the temperature

detected by the thermocouple sling 14. The comparator

circuit 46 outputs a temperature difference signal primarily

representing the polarity of the difference between

the retransmitted temperature related signal and

the selected one of the two reference signals. This temperature

difference signal is modified by a chopper

circuit 56. The chopper circuit 56 is a vibrating switch

energized at the line frequency. The switch chopped

pulses of the temperature difference signals are thereby

synchronized with the sinusoidal variation of the line

power. The phase relationship ofthese pulses to the line

power then depends upon the positive or negative difference

between the sensed temperature signal and the

reference signal.

The pulsed output from the chopper circuit 56 is

applied to an amplifier circuit 58 including voltage amplifiers

60, 62 for the necessary voltage amplification of

the pulsed output. A power amplifier 64 of the amplifier

circuit 58 is for generating sufficient power to drive

servomotor winding 66 with pulses corresponding to

the positive or negative portion of the sinusoidal voltage

provided by transformer 68. However, the power

amplified pulses are transmitted through an interrupt

circuit 70. The interrupt circuit 70 includes a motor

driven cam switch 72, and a shorting relay 74, the

contacts of which are connected across the contacts of

the motor cam switch 72 to stop the interruptor action

of the interrupt circuit 70 when required. Whenever a

cam 75 of cam switch 72 has rotated such that a notch

76 formed in the cam 74 receives a finger 78, a contact

80 provides an electrical connection between the transformer

68 and a selector switch 82 to provide power to

the power amplifier 64 and servomotor circuit 33, when

the selector switch 82 is in an "auto" position. The

"auto" position provides an automatic mode of moving

the crucible 10, the movement depending upon the

temperature of the crucible 10 and the magnitudes of

the reference signals as well as the controlling/timing

circuit 28. The interrupt circuit 70 provides short, infrequent

pulse driving of the servomotor of the servomotor

circuit 30 so that the temperature of the crucible 10

and thermocouple sling 14 has sufficient time to equilibrate

or settle prior to the next pulsed movement, so

that the next movement, if required, will be in the

proper direction.

The direction of movement of the pulley 32, referencing

FIG. 4, hence the direction of vertical movement of

the crucible 10 and thermocouple sling 14 depends upon

the polarity of the pulses outputted by the chopper

4,459,103

5 6

circuit 56, which determines the phase relationship of is then moved upwardly while still under manual conthe

amplified pulses reaching the windings 66 of the trol. The movement of the thermocouple sling 14 is

servomotor. When the pulses have a negative polarity halted when it is approximately 1.5 inches above the

indicating that the reference signal is greater in magni- furnace 36. Next, the thermocouple sling 14 receives the

tude than the magnitude of the sensed temperature sig- 5 crucible 10 containing a weighted sample of coal or

nal, the phase of the voltage across the windings 66 is coke. The selector switch 82 is then set to its "autosuch

that the pulley 32 is driven in a counterclockwise matic" mode with the switch contacts positioned as

direction by the servomotor, lowering the crucible 10 illustrated in FIG..4. At this time, the comparator cirand

thermocouple sling 14 into hotter areas of the fur- cuit 46 compares the sensed temperature signal indicanace.

Conversely, when the pulses have a positive sense 10 tive of a temperature of approximately 100· C., from the

indicating that the referenc.e signal is less·in magnitude recorder device 24, with the first reference signal correthan

the magnitude of the sensed temperature signal, the sponding to 600· C. The first timer 86 is then enabled

phase of the voltage applied· across the windings 66 is with pushbutton 88 and begins to count down from its

such that the pulley 32 is driven in a clockwise sense by preset time period. In the preferred embodiment, the

the servomotor, raising the crucible 10 and thermo- 15 first timer 86 is set for about six (6) minutes.

couple sling 14 into cooler areas of the furnace, or at the Initially during this six minute time period, since the

end out of the furnace. thermocouple sling 14 and crucible 10 are above the

As illustrated in FIG. 4, the energization of the coils furnace 36 and now at a temperature of about 100· C.,

associated with the relays 48 and 74 is controlled by the the first reference signal is greater in magnitude than the

timer circuit 84, assuming the selector switch 82 is in the 20 sensed temperature signal. As a result, downward mo-

"auto" mode. The timer circuit 84 includes a first timer tion phased pulses are generated by the chopper circuit

86 which is enabled by pushbutton 88, and begins to 56 and amplified for driving the servomotor through

count down from a predetermined stored count with the cam switch 72, and the servomotor of the servomorelay

48 connected to the first set-point reference of tor circuit 30 is driven in a downward direction for a

sliding contactor 44 and the interruptor bypass relay 74 25 1/10 second interval during each revolution of the cam

in its open position. The first timer 86 is coupled to a . 75. In a preferred em1:Jodiment, the cam 75 rotates one

second timer 90, a time delay relay 92 and a coil 94. complete revolution each twelve (12) seconds. The

When the predetermined time set in the first timer 86 is interruptor contact 80 provides a relatively slow decompleted,

the output from the first timer energizes the scent of the crucible 10 into the furnace 36 because of

coil 94. The energization ofthis coil 94 changes the state 30 the intermittent energization of the servomotor. This

of the relay 48 so that the first reference is disconnected permits orderly venting of evaporating moisture and

and the second reference signal is applied to the com- other low boiling fractions. If these were allowed to

parator circuit 46. Further, when the first timer 86 times erupt by a faster temperature rise, some sample material

out, the second timer 9Qis enabled to count down for its would be blown out of the crucible 10 thereby destroypredetermined

time interval. At the· beginning of the 35 ing the test.

second timer 90 predetermined time interval, time delay The sensed temperature of the thermocouple sling 14

relay 92 energizes relay coil 96 for six (6) seconds. corresponds to the first reference temperature of 600·

While the coil 96 is energized, the relay 74 is closed and C. after about five minutes of intermittent descent into

the interrupting action of the cam switch 72 is bypassed, the furnace 36, because at this time thermocouple juncso

that the servomotor drives continuously as there is a 40 tions 20, 22 are positioned in the furnace 36 at its 600· C.

difference signal from the comparator circuit 46, caused level. This temperature is maintained for the remaining

by relay 48 shifting to the set-point of sliding contactor one minute of the six minute time period. This tempera-

52, which is higher than the previous set-point of sliding ture is maintained by comparing the sensed temperature

contactor 44. This permits the servomotor to quickly signal with the first reference signal. Any difference in

drive the crucible 10 to the temperature area· corre- 45 magnitude between the sensed tempe~ature signal al)d

sponding to the second set-point, which requires about the first reference signal is used to vertically adjust the

6 seconds, after which time delay relay 92 times out, position of the crucible 10. The direction of vertical

opening relay 74, thereby re-enabling cam switch 72. movement of the crucible 10 and thermocouple sling 14

The second timer 90 continues to operate through the depends upon the polarity of the pulses outputted from

remainder of the desired high temperature period and 50 the chopper circuit 56.

when it times out coil 98 is energized. The energization At the completion of this first six minute time period,

of coil 98 switches open the state of relay 54 so that a the second timer 90 and time delay relay 92 are enabled.

zero reference signal is applied to the comparator cir- The second timer 90 has a time period of about six

cuit 46. In this state of the relay 54, as well as relay 48, minutes associated therewith. With the activation of the

and the contact interruptor 80 bypassed, the crucible 10 55 second timer 90, the coil 96 is also energized which

and sample are quickly moved in a vertically upward closes relay 74 for the six second duration of the time

direction out of the furnace to where the servomotor delay relay 92. In addition, coil 94 is energized. so that

runs into a mechanical stop. relay 48 changes state and the first reference signal is

To further understand the present inventions, a typi- n::moved and the second reference signal, correspondcal

test process is now described. Initially, power is 60 ing to 950· C., is applied to the circuit 46. With the

applied to the furnace 36, the selector switch 82 is closure of relay 74 and the changing to the second referplaced

in "manual" mode, and the thermocouple sling ence signal, downward motion phased chopper pulses

14 is moved using the selector switch 82and switch 83 are continuously applied to the servomotor windings 66

to the bottom of the furnace 36, without the crucible 10 so that the crucible 10 and sample are relatively quickly

held thereby, where the furnace 36 is the hottest. When 65 moved downwardly into the furnace 36. This rapid

the thermocouple sling 14 detects a temperature of movement positions the crucible 10 very quickly in that

about IS· C. above the second predetermined reference portion of the furnace 36 which is at a temperature of

temperature (950·+IS· C.), the thermocouple sling 14 about 950·. Upon completion of this six second time

4,459,103

couple sling. In this regard, the thermocouple sling not

only provides a signal relating to the temperature of the

crucible and the sample contained therein but also supports

the crucible for vertical movement with respect to

5 a furnace. In addition, the control circuitry of the analyzer

permits a proper determination of the volatile matter

content to be made by regulating the rate of temperature

changes and the amount of time that the sample is

subjected to predetermined temperatures. Consequently,

accuracy of the volatile matter content determination

is maximized and reproducibility of results is

enhanced. Furthermore, multiple samples can be analyzed

simultaneously to increase the analytical capacity

and also minimize the amount of hardware needed.

Although the present invention has been described

with reference to a plurality of embodiments, it is

readily appreciated that variations and modifications

can be effected within the spirit and scope of this invention.

What is claimed is:

1. An apparatus for use in analyzing the volatile content

of a sample comprising:

a furnace;

first means for holding the sample;

thermocouple means contacting said first means for

suspendedly supporting said first means and also

providing a temperature signal relating to the temperature

of said first means; and

second means responsive to said temperature signal

for adjusting the position of said first means with

respect to the furnace.

2. An apparatus for use in analyzing the volatile content

of a sample comprising:

first means for holding the sample relative to a heated

container;

thermocouple means for suspendedly supporting said

first means moving therewith and providing a temperature

signal relating to the temperature of said

thermocouple means; and

second means in operative association with said thermocouple

means for moving said thermocouple

means and said first means, the movement of said

first means and said thermocouple means depending

upon the temperature of said thermocouple

means.

3. An apparatus, as claimed in claims 1 or 2, wherein:

said second means includes means for generating a

first reference signal corresponding to a first temperature.

4. An apparatus, as claimed in claims 1 or 2, wherein:

said thermocouple means includes two dissimilar

metal elements joined together at least at one junction.

5. An apparatus, as claimed in claims 1 or 2, wherein

said second means includes:

means for generating a first reference signal corresponding

to a first temperature; and

means responsive to said generating means for comparing

the first reference signal with the temperature

signal provided by said thermocouple means.

6. An apparatus, as claimed in claims 1 or 2, wherein:

said second means includes interrupt means for use in

intermittently moving said first means.

7. An apparatus for use in both supporting a container

and the material contained therein relative to a heating

means and providing an indication ofthe temperature of

said container and the material contained therein comprising;

period, the coil 96 is deenergized and the relay 74 opens.

Any further vertical adjustment of the crucible 10 is

then once again moderated by the cam switch 72 as well

as controlled by any pulses outputted by the chopper

circuit 56.

The second timer 90 like the first timer 86, also normally

has a six (6) minute time period associated therewith.

During this period, which begins immediately

after the completion of the time period associated with

the first timer 86, any necessary vertical adjustment of 10

the crucible 10 is automatically made to maintain the

crucible 10 at a temperature of950° C., the initial adjustment

hastened by bypassing for six seconds the cam

switch 72 using time delay relay 92. At the completion

of this six minute period, the relay 54 opens and the 15

relay 74 is once again closed. When relay 54 is open, the

reference temperature signal to the comparator circuit

46 corresponds to a very low temperature and the

sensed temperature is much greater than that, causing

upward motion chopper pulses. Also, since relay 74 is 20

once again closed, upward phased power pulses are

continuously applied to the servomotor circuit 30

through the relay 74 while bypassing the cam switch 72

in order that the crucible 10 may be quickly raised from

the furnace 36. The crucible 10 can then be removed 25

from the thermocouple sling 14 for further cooling and

subsequent weighing in order to determine the volatile

matter content of the sample contained in the crucible

10. The predetermined time periods set in the first and

second timers and noted in the foregoing discussion 30

have been empirically determined and the use thereof is

intended to maximize the accuracy of the volatile matter

content analysis.

In another preferred arrangement, the recorder device

24, the reference circuit 40, the comparator circuit 35

46, the chopper circuit 56, and the amplifier circuit 58

are time shared with at least two furnaces, servomotor

circuits, thermocouple slings, and crucibles. In such an

embodiment the interrupt circuit 70 is modified to include

a cam switch having two notches, wherein the 40

notches are separated by 1800 to provide a pulse every

six (6) seconds. Another cam with a 50% down profile

and switch are added to effect the transfer ofthe foregoing

control equipment from one furnace to another in a

synchronized manner. Consequently, during! revolu- 45

tion of the cam switch or every six seconds, vertical

adjustment of one of the two crucibles is controlled,

while during the second half of the cam revolution the

other of the two crucibles can be controlled using the

1/10 second pulses which occur once during each six 50

second period. This arrangement results in the chart of

the recorder device 24 being a sequential composite of

the two crucible temperatures while doubling the analytical

capacity of the apparatus.

Although the embodiments discussed herein have 55

been described or illustrated with reference to particular

hardware, such as relays, vacuum tubes and transformers,

it is readily appreciated that other appropriate

electrical hardware can be utilized. With respect to the

recorder device 24, such a device is commercially avail- 60

able from Leeds and Northrup under the name

"SPEED-O-MAX H".

Based on the above disclosure, it is readily discerned

that a number of worthwhile benefits are achieved in

the present invention. A volatile matter content analy- 65

zer is provided for automatically adjusting the position

of a crucible and a sample relative to a furnace by continually

using the temperature sensed by a thermo4,459,103

porting said container means and for providing a

temperature signal relating to the temperature of

the sample; and

driving means in operative association with said thermocouple

sling for moving said container means

and said thermocouple sling relative to said furnace

means depending upon the temperature signal.

14. An apparatus, as claimed in claim 13, and further

comprising:

first means for generating a reference signal;

second means responsive to said first means for comparing

the reference signal to the temperature signal

and for providing an output signal; and

third means communicating with said second means

for intermittently applying the output signal from

said second means to said driving means.

15. An apparatus, as claimed in claim 14, wherein:

said thermocouple sling includes at least one thermocouple

junction where two dissimilar metal elements

are joined together, said thermocouple junction

contacting said container means.

16. An apparatus for use in analyzing the volatile

content of a sample comprising:

furnace means supported on a surface;

container means for holding the sample;

a thermocouple sling in contacting association with

said container means for use in suspendedly supporting

said container means, moving therewith

and providing a temperature signal relating to the

temperature of the sample;

driving means in operative association with said thermocouple

sling for moving said container means

and said thermocouple sling relative to said furnace

means depending upon the temperature signal;

first means for generating a reference signal;

second means responsive to said first means for comparing

the reference signal to the temperature signal

and for providing an output signal; and

third means communicating with said second means

for intermittently applying the output signal from

said second means to said driving means to move

said container means and said thermocouple sling;

said thermocouple sling includes at least one thermocouple

junction where two dissimilar metal elements

are joined together, said thermocouple junction

adapted to contact said container; and

said thermocouple sling includes first and second

metal elements arranged to form an opening between

portions of said metal elements, said opening

adapted to receive the crucible.

* * * * *

a thermocouple sling in releasable contacting association

with the container having material contained

therein, said thermocouple sling suspendedly supporting

said container and the material contained

therein relative to a surface but spaced therefrom, 5

and said thermocouple sling generating a temperature

signal relating to the temperature of said container

and the material contained therein, whereby

means responsive to said temperature signal adjusts

the thermocouple sling relative to the container. 10

8. An apparatus, as claimed in claim 7, wherein:

said thermocouple sling includes at least one thermocouple

junction where two dissimilar metals are

joined together, said thermocouple junction

adapted to contact said container.

9. An apparatus, as claimed in claim 7, wherein:

said thermocouple sling includes first and second

metals arranged to form an opening between portions

of said metals, said opening adapted to receive

said container.

10. In a system for determining the volatile matter

content of a coal or coke sample including a furnace, a

crucible for holding the sample, and means for use in

moving the crucible and sample, a device comprising:

a thermocouple sling in releasable operative associa- 25

tion with said crucible for contacting and suspendedly

supporting said crucible, said thermocouple

sling being movable by said moving means with

respect to said furnace together with said crucible

and said sample, and said thermocouple sling gen- 30

erating a temperature signal relating to the temperature

of said crucible, said sample, and said thermocouple

sling for controlling movement of said moving

means in response to said temperature signal.

11. A device, as claimed in claim 10, wherein:

said thermocouple sling includes at least one thermocouple

junction where two dissimilar metal elements

are joined together, said thermocouple junction

contacting said crucible.

12. A device, as claimed in claim 10, wherein:

said thermocouple sling includes first and second

metal elements arranged to form an opening between

portions of said metal elements, said opening

adapted to receive said crucible.

13. An apparatus for use in analyzing the volatile 45

content of a sample adapted to be positioned relative to

a furnace, comprising:

furnace means supported on a surface;

container means for holding the sample;

a thermocouple sling in contacting association with 50

said container means for use in suspendedly sup-