Parr Instrument 6200 - Manual (Page 64)

65
6200
Calorimeter Operating Instruction Manual
Acid and
Sulfur
Corrections
Continued
Users may find it convenient to enter a
fixed value for the acid correction and avoid
the need to determine this correction for
each test. Use of a fixed value for the acid
correction is highly recommended. Fixed
acid corrections can be entered when Fixed
Acid - Thermochemical Corrections, is set to
ON. A correction of 10 calories is a good
number for the fixed nitric acid value. For
most work, it is recommended to set “Acid
Value is Nitric Acid Only”, in Calculation
Factors to ON. Total errors of more than 3
calories will seldom occur when using fixed
nitric acid corrections.
Fixed sulfur corrections can be entered
if a series of samples contain a constant
amount of sulfur. Fixed sulfur corrections
can be entered when Fixed Sulfur -
Thermochemical Corrections, is set to ON
and then enter percent sulfur as indicated
on this line. Any errors will be proportional
to the difference between the
actual and assumed value for
sulfur.
For ordinary work where benzoic acid is
used, for standardizing the calorimeter, the
Fixed Sulfur Correction, for
Standardizations should be ON applying a
fixed value of 0.0 to all standardization
tests. Benzoic acid contains no sulfur.
Please note that the values entered into
the test report appear as entered in the
report. Values for e
1
, e
2
and e
3
are
calculated and used as energy corrections
in accordance with the formulas and
settings given above. The formulas used
above to arrive at e
1
or e
2
are not the same
as the formulas used for e
1
and e
2
which
appear in most ASTM bomb calorimetric
procedures. However, the sum of e
1
and e
2
,
above, is equal to the sum of the ASTM
treatment of e
1
and e
2
.
Table B-1
Settings for ISO & BSI Methods
Page Line Setting Value
Thermochemical
Corrections
Fixed Acid STD
Fixed Sulfur STD
Fixed Acid DET
Fixed Sulfur DET
Off
Off
Off
Off 13
7
13
7
Calculation Factors Acid is Nitric Only
Acid Multiplier
Sulfur Value is Percent
Sulfur Multiplier
User Offset Correction
Offset Value
On
Off
On
0.154
0.1
-43.5
B-5
APPENDIX B