Page 1
204M
1341
Plain Jacket Calorimeter
Operating Instruction Manual
Page 2
Table of Contents
Preface 3
Scope 3
Related Instructions 3
Important Information 3
Intended Usage 3
Explanation of Symbols 4
Safety Information 4
General Specifications 4
Environmental Conditions 4
Provisions for Lifting and Carrying 4
Assemble the Calorimeter 5
Operating the 1108 Oxygen Vessel 5
Operating the Calorimeter 6
Discussion of Calculations 11
Acid Correction 11
Sulfur Correction 11
Fuse Wire Correction 11
Radiation Correction 11
Magnitude of Errors 12
Maintenance 12
Calorimeter Maintenance 12
General Cleaning Instructions 12
Fuse Ratings 12
Electric Ignition Problems 12
6772 Calorimetric Thermometer 13
Electrical Hookup of Thermometer to Calorimeter 14
Calculating the Heat of Combustion 8
Assembly of Data 8
Temperature Rise 8
Gross Heat of Combustion 9
Conversion to Other Bases 9
Standardizing the Calorimeter 10
The Energy Equivalent Factor 10
Standard Samples 10
Standardization Procedure 10
Parts for the 1341 Calorimeter 15
Customer Service
Questions concerning the installation or operation
of this instrument can be answered by the Parr
Customer Service Department:
1-309-762-7716 • 1-800-872-7720
Fax: 1-309-762-9453
E-mail: parr@parrinst.com
www.parrinst.com
2
Parr Instrument Company
Page 3
1341 Plain Jacket Calorimeter
Preface
Scope
These instructions cover the steps to be taken in
setting up and operating a Parr 1341 Plain Jacket
Calorimeter. The user should study these instructions carefully before starting to use the calorimeter
so that they will fully understand the capabilities of
the equipment, and be well aware of the safety precautions to be observed in its operation. Instructions
covering the operation of the 1108 Oxygen Combustion Vessel and the use of other related apparatus
are provided in separate instruction manuals listed
below. The separate manuals which apply to a
particular calorimeter installation should be added
to and made a part of these instructions.
Related Instructions
No. Description
205M Operating Instructions for the 1108
Oxygen Combustion Vessel
207M Analytical Methods for Oxygen Bombs
545M Operating Instructions for 6775/6775A
Digital Thermometer
201M Limited Warranty
Important Information
Your Parr 1341 Plain Jacket Calorimeter has been designed with function, reliability, and safety in mind.
It is your responsibility to install it in conformance
with local electrical codes.
This manual contains important operating and
safety information. You must carefully read and understand the contents of this manual prior to the use
of this equipment. For safe operation, please pay
attention to the alert signals throughout the manual.
Intended Usage
Do not use this equipment for anything other than
its intended usage. Protection provided by the
equipment may be impaired if used in a manner not
specified by Parr Instrument Company. This instrument is to be used indoors.
Note About Nomenclature:
Historically, burning a sample enclosed in a
high pressure oxygen environment is known
as Oxygen Bomb Calorimetry and the vessel
containing the sample is known as an Oxygen
Bomb. The terms bomb and vessel are used
interchangeably.
www.parrinst.com
3
Page 4
1341 Plain Jacket Calorimeter
Explanation of Symbols
This CAUTION symbol may be present on the Product Instrumentation and
literature. If present on the product, the user must consult the appropriate
part of the accompanying product literature for more information.
Protective Earth (PE) terminal. Provided for connection of the Protective
Earth (green or green/yellow) supply system conductor.
Safety Information
To avoid electrical shock, always:
1. Use a properly grounded electrical outlet of
correct voltage and current handling capability.
2. Ensure that the equipment is connected to
electrical service according to local national
electrical codes. Failure to properly connect may
create a fire or shock hazard.
3. For continued protection against possible
hazard, replace fuses with same type and rating
of fuse.
4. Disconnect from the power supply before
maintenance or servicing.
To avoid personal injury:
1. Do not use in the presence of flammable or
combustible materials; fire or explosion may
result. This device contains components which
may ignite such material.
2. Refer servicing to qualified personnel.
General Specifications
Electrical Ratings
Plain Jacket Calorimeters:
Model 1341EB: 115VAC, 0.30 Amps, 60 Hz
Model 1341EE: 230VAC, 0.15 Amps, 50/60 Hz
Before connecting the calorimeter to an electrical
outlet, the user must be certain that the electrical
outlet has an earth ground connection and that the
line, load and other characteristics of the installation
do not exceed the following limits:
Voltage: Fluctuations in the line voltage should not
exceed 10% of the rated nominal voltage shown on
the data plate.
Frequency: Calorimeters can be operated from
either a 50 or 60 Hertz power supply without affecting their operation or calibration.
Current: The total current drawn should not exceed
the rating shown on the data plate on the calorimeter by more than 10 percent.
Environmental Conditions
Operating: 15 ºC to 40 ºC; maximum relative humidity of 80% non-condensing.
Installation Category II (over voltage) in accordance
with IEC 664.
Pollution degree 2 in accordance with IEC 664.
Altitude Limit: 2,000 meters.
Storage: -25 ºC and 65 ºC; 10% to 85% relative
humidity.
Ignition Units:
2901EB: 115 VAC, 50/60 Hz, 4.0 Amps
2901EE: 230 VAC, 50/60 Hz, 2.0 Amps
2901EU: 230 VAC, 50/60 Hz, 2.0 Amps
2901EX: 230 VAC, 50/60 Hz, 2.0 Amps
2901EZ: 230 VAC, 50/60 Hz, 2.0 Amps
4
Parr Instrument Company
Provisions for Lifting and Carrying
Before moving the instrument, disconnect all connections from the rear of the apparatus. Lift the
instrument by grabbing underneath each corner.
Page 5
1341 Plain Jacket Calorimeter
Assemble the Calorimeter
1. Unpack the calorimeter carefully and check the
individual parts against the packing list. If shipping damage is discovered, report it immediately to the delivering carrier. Unpack the jacket
first and set it on a sturdy bench or table in a
location that is reasonably free from drafts and
is protected from sources of radiant heat, preferably in an air conditioned room. Temperature
changes in the room should be minimal.
There should be convenient access to running
water, to a drain and to an appropriate grounded
electrical outlet. About 8 square feet of workspace will be required. Access to a chemical balance sensitive to 0.1 mg and to a solution, trip or
torsion balance capable of weighing up to 3.0 kg
with 0.1 g sensitivity will be required. A standard 1A cylinder with a purity of 99.5% is usually
sufficient for bomb combustion purposes.
2. Set the cover on the jacket. Remove the two
screws from the side of the jacket and attach the
stirrer drive motor. Check the stirrer shaft to be
sure that it turns freely and slip the drive belt
onto the motor and stirrer pulleys.
3. Assemble the cover support stands. Two stands
are furnished, each consisting of a base, a support rod and ring to be clamped to the upper end
of the rod. The A37A stand with the large ring is
used to support the calorimeter cover when it is
removed from the jacket, while the A38A stand
with the smaller ring supports the bomb head
when attaching the fuse wire and arranging the
fuel capsule.
4. Install the thermistor by sliding it through the
opening in the calorimeter cover. Adjust the
length of the thermistor to match the length of
the stirring shaft. Hand tighten the nut to secure
the thermistor.
Note: Do not over tighten the nut.
The single dimple must always face forward
when setting the bucket in the jacket.
6. Connect the ignition unit. While any electrical
system capable of furnishing approximately 23
volts can be used to ignite the fuse in the oxygen
bomb, most users will prefer to use a Parr 2901
Ignition Unit for this purpose. This unit operates
from any standard electrical outlet to provide the
proper low voltage firing current, providing also
a convenient push switch, indicating lamp and
connecting terminals.
Connect one of the lead wires from the calorimeter jacket to the terminal labeled “10CM”.
Connect the second lead to the terminal labeled
“Common”. Plug the power cord into an appropriately grounded electrical outlet. The power
supply cord is the main electrical disconnect
device for the ignition unit. After the unit has
been plugged into an outlet do not press the
firing button unless the lead wires inside the
jacket are connected to the combustion vessel.
Caution!
If the bare terminals on these wires happen
to be in contact with each other or with a
metal object when the circuit is closed, the
resulting short-circuit may cause serious
damage to the ignition system.
7. Attach the oxygen filling connection. Unscrew
the protecting cap from the oxygen tank and
inspect the threads on the valve outlet to be sure
they are clean and in good condition. Place the
ball end of the 1825 Oxygen Filling Connection
into the outlet socket and draw up the union
nut tightly with a wrench, keeping the 0-55 atm.
gage in an upright position.
Operating instructions for the 1825 Oxygen Filling
Connection are provided in Instruction Manual
205M for the 1108 Oxygen Combustion Vessel.
Once installed, the thermistor can remain attached to the cover during all operations. Do not
lay the cover on the tabletop. Always set it in
the supporting ring on the A37A stand to protect
the thermistor and stirring shafts.
5. Check the calorimeter bucket, noting the three
dimples in the bottom of the bucket which rest
on supporting pins in the bottom of the jacket.
Operating the 1108 Oxygen Vessel
Detailed instructions for preparing the sample and
charging the 1108 Oxygen Combustion Vessel are
given in Instruction Manual, No. 205M. Follow
these instructions carefully, giving particular attention to the precautions to be observed in charging
and handling the bomb.
www.parrinst.com
5
Page 6
1341 Plain Jacket Calorimeter
Operating the Calorimeter
All operations required to test a sample or to standardize the 1341 Plain Jacket Calorimeter should
proceed step-wise in the following manner:
1. Prepare the sample and charge the oxygen
combustion vessel as described in Instruction
Manual No. 205M.
2. Fill the calorimeter bucket by first taring the dry
bucket on a solution or trip balance; then add
2000(+/-0.5) grams of water. Distilled water is
preferred, but demineralized or tap water containing less than 250 ppm of dissolved solid is
satisfactory. The water temperature should be
approximately 1.5°C below room temperature,
but this can be varied to suit the operator’s preference. It is not necessary to use exactly 2000
grams, but the amount selected must be duplicated within +/-0.5 gram for each run. Instead
of weighing the bucket it can be filled from an
automatic pipet or from any other volumetric
device if the repeatability of the filling system is
within +/-0.5 ml. and the water temperature is
held within a 1ºC range.
3. Set the bucket in the calorimeter. Attach the
lifting handle to the two holes in the side of the
screw cap and partially lower the bomb in the
water. Handle the bomb carefully during this operation so that the sample will not be disturbed.
Push the two ignition lead wires into the terminal sockets on the bomb head. Orient the wires
away from the stirrer shaft so they do not become tangled in the stirring mechanism. Lower
the bomb completely into the water with its feet
spanning the circular boss in the bottom of the
bucket. Remove the lifting handle and shake any
drops of water into the bucket and check for gas
bubbles.
4. Set the cover on the jacket. Turn the stirrer by
hand to be sure that it runs freely; then slip the
drive belt onto the pulleys and start the motor.
Turn on the 6775 Digital Thermometer.
5. Let the stirrer run for 5 minutes to reach equilib-
rium before starting a measured run. At the end
of this period record the time on the timer of the
6775 Digital Thermometer and read the temperature.
6. Read and record temperatures at one-minute
intervals for 5 minutes. Then, at the start of the
6th minute…
7. Stand back from the calorimeter and fire the
bomb by pressing the ignition button and holding it down until the indicator light goes out.
Normally the light will glow for only about ½
second but release the button within 5 seconds
regardless of the light.
Caution!
Do not have the head, hands or any parts of
the body over the calorimeter when firing
the bomb; and continue to stand clear for 30
seconds after firing.
8. The bucket temperature will start to rise within
20 seconds after firing. This rise will be rapid
during the first few minutes; then it will become
slower as the temperature approaches a stable
maximum as shown by the typical temperature
rise curve below. It is not necessary to plot a
similar curve for each test, but accurate time and
temperature observations must be recorded to
identify certain points needed to calculate the
calorific value of the sample.
9. Measure the time required to reach 60 percent
of the total rise by estimating the temperature at
the 60% point and observing the time when the
temperature reading reaches that point. If the
60% point cannot be estimated before ignition,
take temperature readings at 45, 60, 75, 90 and
105 seconds after firing and interpolate between
these readings to identify the 60% point after the
total rise has been measured.
10. After the rapid rise period (about 4 or 5 min-
utes after ignition) record temperatures at one
minute intervals until the difference between
successive readings has been constant for five
minutes. Usually the temperature will reach a
maximum; then drop very slowly. But this is
not always true since a low starting temperature
may result in a slow continuous rise without
reaching a maximum. As stated above, the dif-
ference between successive readings must be
noted and the readings continued at one-minute
intervals until the rate of the temperature change
becomes constant over a period of 5 minutes.
6
Parr Instrument Company
Page 7
1341 Plain Jacket Calorimeter
Graph displaying typical temperature rise curve
11. After the last temperature reading, stop the
motor, remove the belt and lift the cover from
the calorimeter. Wipe the thermistor shaft and
stirrer with a clean cloth and set the cover on
the A37A support stand. Lift the bomb out of the
bucket; remove the ignition leads and wipe the
bomb with a clean towel.
12. Open the knurled knob on the bomb head to
release the gas pressure before attempting to
remove the cap. This release should proceed
slowly over a period of not less than one minute
to avoid entrainment losses. After all pressure
has been released, unscrew the cap; lift the head
out of the cylinder and place it on the support
stand. Examine the interior of the bomb for soot
or other evidence of incomplete combustion. If
such evidence is found, the test will have to be
discarded.
Caution!
Do not have any part of the body in the
pressure relief path.
13. Wash all interior surfaces of the bomb with a jet
of distilled water and collect the washings in a
beaker.
14. Remove all unburned pieces of fuse wire from
the bomb electrodes; straighten them and
measure their combined length in centimeters.
Subtract this length from the initial length of 10
centimeters and enter this quantity on the data
sheet as the net amount of wire burned. Alternatively, the correction in calories is located on
the card of the 45C10 fuse wire.
15. Titrate the bomb washings with a standard sodium carbonate solution using methyl orange or
methyl red indicator. A 0.0709N sodium carbonate solution is recommended for this titration to
simplify the calculation. This is prepared by dissolving 3.76 grams Na2CO3 in water and diluting
to one liter NaOH or KOH solutions of the same
normality may be used.
16. Analyze the bomb washings to determine the
sulfur content of the sample if it exceeds 0.1 per
cent. Methods for determining sulfur are discussed in Instruction Manual No. 207M.
www.parrinst.com
7
Page 8
1341 Plain Jacket Calorimeter
Calculating the Heat of Combustion
Assembly of Data
The following data should be available at the completion of a test in a 1341 calorimeter:
a = time of firing
b = time (to nearest 0.1 min.) when the
temperature reaches 60 per cent of the
total rise
c = time at beginning of period (after the
temperature rise) in which the rate of
temperature change has become constant
t
= temperature at time of firing
a
t
= temperature at time c
c
r
= rate (temperature units per minute) at
1
r
2
c
1
c
2
which the temperature was rising during
the 5-min. period before firing
= rate (temperature units per minute) at
which the temperature was rising during
the 5-min. period after time
c. If the temperature was falling instead
of rising after time c, r is negative and
the quantity -r (c-b) becomes positive
and must be added when computing the
corrected temperature rise
= milliliters of standard alkali solution used
in the acid titration
= percentage of sulfur in the sample
Temperature Rise
Compute the net corrected temperature rise, t, by
substituting in the following equation:
t = tc - ta - r1 (b-a) - r2 (c-b)
Thermochemical Corrections
Compute the following for each test:
e1= correction in calories for heat of forma-
tion of nitric acid (HNO3 )
= c1 if 0.0709N alkali was used for the
titration
e2= correction in calories for heat of forma-
tion of sulfuric acid (H2SO4)
= (13.7) (c2) (m)
e3= correction in calories for heat of combus-
tion of fuse wire
= (2.3) (c3) when using Parr 45C10 nickel
chromium fuse wire, or
= (2.7) (c3) when using No. 34 B. & S. gage
iron fuse wire
c
= centimeters of fuse wire consumed in
3
firing
W = energy equivalent of the calorimeter,
determined under standardization
M = mass of sample in grams
8
Parr Instrument Company
Page 9
1341 Plain Jacket Calorimeter
Gross Heat of Combustion
Compute the gross heat of combustion, Hg, in
calories per gram by substituting in the following
equation:
H
g
t W - e1 - e2 - e
=
m
3
Example:
a = 1:44:00 = 1:44.0
b = 1:45:24 = 1:45.2
c = 1:52:00 = 1:52.0
t
t
r
= 24.428 + .004 = 24.432 °C
a
= 27.654 + .008 = 27.662 °C
c
= + .010 °C /5 min. = + .002 °C /min.
1
r2 = - .004 °C /5 min. = .001 °C /min.
c
c
c
= 23.9 ml.
1
= 1.02% Sulfur
2
= 7.6 cm. Parr 45C10 wire
3
W = 2426 calories/ °C
m = .9936 grams
t = 27.662-24.432-(.002) (1.4)-(-.001) (6.6)
= 3.234 °C
e1 = 23.9 calories
e2 = (13.7) (1.02) (.9936) = 13.9 calories
e3 = (2.3) (7.6) = 17.5 calories
(3.234) (2426) – 23.9 – 13.9 – 17.5
Hg =
.9936
= 7841 calories/ gram
= (1.8) (7841) = 14,114 Btu/lb
Conversion to Other Bases
The calculations described above give the calorific
value of the sample with moisture as it existed
when the sample was weighed. For example, if an
air-dried coal sample was tested, the results will be
in terms of heat units per weight of air-dry sample.
This can be converted to a moisture free or other
dry basis by determining the moisture content of
the air-dry sample and using conversion formulae
published in ASTM Method D3180 and in other
references on fuel technology.
The calorific value obtained in a calorimeter test
represents the gross heat of combustion for the
sample. This is the heat produced when the sample
burns, plus the heat given up when the newly
formed water vapor condenses and cools to the
temperature of the bomb. In nearly all industrial
operations this water vapor escapes as steam in the
flue gases and the latent heat of vaporization which
it contains is not available for useful work. The net
heat of combustion obtained by subtracting the
latent heat from the gross calorific value is therefore
an important figure in power plant calculations.
If the percentage of hydrogen, H, in the sample is
known, the net heat of combustion, Hn in Btu per
pound can be calculated as follows:
Hn = 1.8Hg - 91.23H (ASTM D240)
www.parrinst.com
9
Page 10
1341 Plain Jacket Calorimeter
Standardizing the Calorimeter
The Energy Equivalent Factor
The term “standardization” as used here denotes
the operation of the calorimeter with a standard
sample from which the energy equivalent or effective heat capacity for the system can be determined.
The energy equivalent factor (W) represents the
energy required to raise the temperature of the
calorimeter one degree, usually expressed as
calories per degree Celsius. This factor for the 1341
calorimeter with an 1108 Oxygen Combustion Vessel
will usually fall within a range from 2410 to 2430
calories per degree Celsius, with the exact value for
each installation to be determined by the user. This
requires a series of at least four standardization
tests (and preferably more) from which an average
can be taken to represent the true W value for the
user’s calorimeter. This will provide a factor which
can be used with confidence in subsequent tests
with unknown materials. Standardization tests
should always be repeated after changing any parts
of the calorimeter, and occasionally as a check on
both the calorimeter and the operating technique.
Standard Samples
A vial of 100 one-gram benzoic acid pellets is furnished with each calorimeter for standardization
purposes. Additional benzoic acid pellets or powder
can be obtained from Parr. For high precision measurements, a primary standard benzoic acid powder
can be purchased from the National Institute of
Standards and Technology (NIST), Washington, D.C.
The NIST also offers standard 2,2,4-trimethly-pentane (Isooctane) as a calorific standard for testing
volatile fuels.
Caution!
Benzoic acid must always be compressed
into a pellet before it is burned in an oxygen
bomb to avoid possible damage from rapid
combustion of the loose powder.
Compressing benzoic acid into a pellet is best
accomplished by using a Parr 2811 Pellet Press. If a
pellet press is not available, melt the powder into a
lump by heating it carefully to the melting point, but
do not overheat the powder as this will change the
calorific value.
Standardization Procedure
The procedure for a standardization test is exactly
the same as for testing a fuel sample. Use a pellet
of calorific grade benzoic acid weighing not less
than 0.9 nor more than 1.25 grams. Determine the
corrected temperature rise, t, from the observed test
data, also titrate the bomb washings to determine
the nitric acid correction and measure the unburned
fuse wire. Compute the energy equivalent by
substituting in the following equation:
W =
Hm+ e1+ e
3
t
W = energy equivalent of the calorimeter in
calories per °C (Centigrade)
H = heat of combustion of the standard ben-
zoic acid sample in calories per gram
m = mass of the standard benzoic acid
sample in grams
t = net corrected temperature rise in °C
e
= correction for heat of formation of nitric
1
acid in calories
e
= correction for heat of combustion of the
3
firing wire in calories
Example:
Standardization with a 1.1651 gram benzoic acid
sample (6318 cal/ gm) produced a net corrected temperature rise of 3.047 °C. The acid titration required
11.9 ml of standard alkali and 8 cm of fuse wire were
consumed in the firing. Substituting in the standardization equation:
H = 6318 cal/ gram
m = 1.1651 gram
e
e
= (11.9 ml) (1 cal/ ml) = 11.9 cal
1
= (8 cm) (2.3 cal/ cm) = 18.4 cal
3
t = 3.047º C
W = (6318) (1.1651) + 11.9 + 18.4
3.047
= 2426 cal per °C
10
Parr Instrument Company
Page 11
1341 Plain Jacket Calorimeter
Discussion of Calculations
Acid Correction
Since combustion in the bomb takes place in an
atmosphere of nearly pure oxygen at high temperature and pressure, several reactions take place
which would not occur in burning the same material
under normal atmospheric conditions. These side
reactions are important because they generate an
appreciable amount of heat which cannot be credited to the sample, and for which a correction must
be made.
For example, in the normal combustion of coal, all
sulfur is oxidized and liberated as SO2 but nitrogen
in the material usually is not affected. Likewise, no
change occurs in the nitrogen of the air required
for normal combustion. But, when the same coal is
burned in the oxygen combustion vessel, oxidation
of the sulfur is carried further to form SO3 which
combines with water vapor to form H2SO4; and
some of the nitrogen in the bomb is also oxidized
and combined with water vapor to form HNO3.
These two side reactions result in acids within the
bomb, and require a correction to account for the
heat liberated in their formation.
In computing the correction for acid formation it
is assumed that all of the acid titrated is nitric acid
(HNO3), and that the heat of formation of 0.1N HNO3
under bomb conditions is -14.1 Kcal per mol. Obviously, if sulfuric acid is also present, part of the
correction for H2SO4 is included in the nitric acid
correction. The sulfur correction described below
takes care of the difference between the heats of
formation of nitric and sulfuric acids.
Sulfur Correction
A correction of 1.4 Kcal must be applied for each
gram of sulfur converted to sulfuric acid. This is
based upon the heat of formation of 0.17N H2SO4
which is -72.2 Kcal per mol. But a correction of 2 X
14.1 Kcal per mol of sulfur is included in the nitric
acid correction. Therefore the additional correction
which must be applied for sulfur will be 72.2-(2 X
14.1) or 44.0 Kcal per mol, or 1.37 Kcal per gram of
sulfur. For convenience, this is expressed as 13.7
calories for each percentage point of sulfur per gram
of sample.
Fuse Wire Correction
The wire used as a fuse for igniting the sample is
partly consumed in the combustion. Thus the fuse
generates heat both by the resistance it offers to the
electric firing current, and by the heat of combustion
of that portion of the wire which is burned. It can be
assumed that the heat input from the electric firing
current will be the same when standardizing the
calorimeter as when testing an unknown sample,
and this small amount of energy therefore requires
no correction. However, it will be found that the
amount of wire consumed will vary from test to test,
therefore a correction must be made to account for
the heat of combustion of the metal.
The amount of wire taking part in the combustion is
determined by subtracting the length of the recovered unburned portion from the original length of 10
cm. The correction is then computed for the burned
portion by assuming a heat of combustion of 2.3
calories per cm. for Parr 45C10 (No. 34 B & S gage
“Chromel C”) wire, or 2.7 calories per cm for No. 34
B & S gage iron wire.
Radiation Correction
The method recommended for calculating the
correction for heat gain or loss from a plain jacket
calorimeter is that specified by the American Society
for Testing and Materials as published under ASTM
Designations D240 and D3286. It is based upon the
work of Dr. H.C. Dickinson at the National Bureau of
Standards who showed that the amount of heat leak
during a test could be approximated by assuming
that the calorimeter is heated by its surroundings
during the first 63 percent of the temperature
rise at a rate equal to that measured during the
5-minute preperiod. The method then assumes that
the cooling (or heating) rate during the remaining
37 per cent of the rise is the same as the rate
observed during the 5-minute postperiod. For most
experimental work the dividing point between these
two periods is taken as that point in time, b, when
the temperature has reached six-tenths (instead
of 63%) of the total rise. Note that these two time
intervals must be expressed in minutes and decimal
fractions (Example: 1.4 min. and 6.6 min.).
www.parrinst.com
11
Page 12
1341 Plain Jacket Calorimeter
Magnitude of Errors
The following examples illustrate the magnitude
of errors which may result from faulty calorimeter
operations. They are based upon an assumed test
in which a 1.0000 gram sample produced a 2.800 ºC
temperature rise in a calorimeter having an energy
equivalent of 2400 calories per °C.
• An error of 1 milliliter in making the acid titration
will change the thermal value 1.0 cal.
• An error of 1 centimeter in measuring the
amount of fuse wire burned will change the
thermal value 2.3 cal.
• An error of 1 gram in measuring the 2 kilograms
of water will change the thermal value 2.8 cal.
• An error of 1 milligram in weighing the sample
will change the thermal value 6.7 cal.
• An error of 0.002 ºC in measuring the temperature rise will change the thermal value 4.8 cal.
If all of these errors were in the same direction, the
total error would be 17.6 cal.
Maintenance
Calorimeter Maintenance
The high polished chrome finish on the calorimeter
bucket is needed to minimize heat transfer. If this
finish becomes dull, the bucket should be replaced.
Also check the bucket stirrer frequently to be sure
that it turns freely. Any drag or friction in the stirrer
will cause slow and erratic temperature response
in the calorimeter. Add a few drops of machine oil
annually to the small hole in the top of the stirrer
assembly. Move the shaft of the assembly up and
down to distribute the oil thoroughly.
General Cleaning Instructions
Wipe exterior surfaces with lightly dampened cloth
containing mild soap solution.
Fuse Ratings
The replacement of protective fuses should be
performed by qualified personnel.
Part No. 139E21 used in Ignition Unit 2901EB:
Slow blow, 5.0 Amps, 250 VAC
Part No. 139E8 used in Ignition Unit 2901EE:
Slow blow, 2.5 Amps, 250 VAC
Electric Ignition Problems
If the indicator light does not come on when the
firing button is pressed on the ignition unit there is
either an open circuit in the system or a fault on the
A1580E circuit board. An open circuit can usually
be located with an ohmmeter. Flex the lead wires
during any continuity check as the wires may be
broken and making only intermittent contact. If the
red indicator light glows during ignition but the fuse
wire does not burn, check the system for a voltage
leak to ground, most likely in the insulated electrode
on the bomb head. Check the electrode using the
high impedance scale on an ohmmeter and replace
the electrode insulator and seal if leakage is indicated.
If test methods for hazardous materials require the
operator to stand away from the calorimeter when
firing the bomb, move the ignition unit to a protected location and add longer wires to the calorimeter.
Although remote firing is not necessary for most
samples, the operator should always step back from
the calorimeter when firing the bomb.
12
Caution!
Do not have the head, hands or any parts of
the body over the calorimeter when firing
the bomb; and continue to stand clear for 30
seconds after firing.
Parr Instrument Company
Page 13
1341 Plain Jacket Calorimeter
6772 Calorimetric Thermometer
To improve the precision and simplify the procedure for measuring and recording the temperature
rise in a 1341 Calorimeter, Parr offers the 6772 Calorimetric Thermometer. Readings are taken with
a thermistor sealed in a stainless steel probe. This two-channel precision calorimetric thermometer
features Parr’s newest generation microprocessor control. The thermometer uses a Linux operating system with communication and file management systems comparable to a PC. A bright, color,
touch screen display and data input system utilizes a graphical interface for easy instrument setup
and operation. A USB port is available for use with a balance, printer, or barcode reader. (For more
information on barcode capability, please contact Parr’s sales staff.) An Ethernet port is available for
data transfer using TCP/IP communications. No additional ignition source is required as the 6772
Calorimetric Thermometer acts as an ignition unit.
Specifications:
• Thermistor Probe
• One Probe – Standard, Two Probes – Optional
• 0.0001 °C Temperature Resolution
• Absolute Accuracy:
±0.1 °C (without calibration)
±0.05 °C (with calibration)
• Repeatability:
±0.002 °C (Single Point)
• Linearity:
±0.002 °C (10 °C Span)
• SD memory and network communications
• Balance & Printer Port: USB
• Updates via the Internet
Please refer to Parr Bulletin 6700 for complete details on the 6772 Calorimetric Thermometer.
www.parrinst.com
13
Page 14
1341 Plain Jacket Calorimeter
Electrical Hookup of 6772 Calorimetric Thermometer to 1341 Calorimeter
14
Parr Instrument Company
Page 15
Parts for the 1341 Calorimeter
1341 Plain Jacket Calorimeter
Key
No.
1
2 355C Motor Pulley
3 37M2 Stirrer Drive Belt
4 37C2 Stirrer Pulley
5 A27A Stirrer Bearing Assembly
6 A468E Ignition Wire
7 A30A3 Stirrer Shaft with Impeller
8 A391DD Oval Bucket
9 A1100DD Calorimeter Jacket with Cover
10 11 0 8 Oxygen Combustion Vessel
11 182VBAD Male Connector
12 1168E2 Thermistor
Part No. Description
A50MEB
A50MEE
Motor Assembly with Pulley, 115V 60 Hz
Motor Assembly with Pulley, 230V 50/60 Hz
3
4
2
12
5
11
1
7
8
6
6
9
10
www.parrinst.com
15
Page 16
204M R09 05/27/14
Loading...