Jacket Designs
Sample
Fired
Controlled
Jacket
Calorimeter
Temperature
Time
P
arr Series 6000 Oxygen Bomb Calorimeters described in this brochure feature a high degree
of automation with touch screen operation, Linux operating system and fifth generation
microprocessor control.
Sample
Fired
Measured
Jacket
Calorimeter
Temperature
Time
Calculated
Jacket
Calorimeter
Temperature
Time
Sample
Fired
Isoperibol Calorimetry
An isoperibol calorimeter is one
where the surrounding jacket is
maintained at a constant tem-
perature while the temperature
of the bomb and bucket rise as
heat is released by the combus-
tion. The Model 6400 and 6200
Calorimeters are true isoperibol
calorimeters. In these implemen-
tations, a controlled temperature
jacket, completely surrounds
the combustion bomb and its
“bucket”. A microprocessor-
based controller monitors both
the temperature of the bucket
and the jacket and performs the
necessary heat leak corrections
that result from differences in
these two temperatures. These
corrections are applied continu-
ously in real-time throughout
the test rather than as a final
correction based on pre and
post test measurements.
Continuously Compensated
Calorimetry
The Parr 6100 Calorimeter
takes advantage of the real
time, continuously corrected
method developed by Parr. No
attempt is made in the Model
6100 Calorimeter to establish
the constant jacket temperature
required for isoperibol calorim-
etry. Instead, the temperature
of the jacket is continuously
monitored and real time heat
leak corrections are applied
based upon the temperature dif-
ference between the bucket and
the actual temperature of the
jacket. While this method is not
truly an isoperibol method, its
real time correction procedure
achieves the same purpose with
nearly equal results. What it can
not do is match the temperature
uniformity of a circulating water
jacket.
Compensated Calorimetry
The Parr 6772 Precision
Thermometer, serving as a
controller for the 1341, 6725
and 6755 Calorimeters, uses
yet another approach to emu-
late the isoperibol calorimetric
method. In these calorimeter
systems, the heat leak is pre-
cisely measured during the
calorimetric pre-period. This
evaluation results in an esti-
mate of the effective, average
temperature of the calorim-
eter surroundings. This tem-
perature value is then used
throughout the test interval to
provide the calorimeter heat
leak correction. While not as
robust as either of the other
two methods outlined above,
it harnesses the computing
power of the controller, with
no additional hardware costs,
to provide heat leak correc-
tion capability that is almost
identical to the approach
used when non-electronic
thermometry and manual
calorimetric techniques are
employed.
P a r r I n s t r u m e n t C o m p a n y
6
w w w . p a r r i n s t . c o m
