Parr Instrument 6400 - Manual (Page 39)

Menu Descriptions
6400 4
w w w . p a r r i n s t . c o m 37
Calculation Factors: Accesses the Calculation Fac-
tors sub-menu, which provides for setting a number
of options for the way the thermochemical correc-
tions are applied.
Calculation Factors Menu
Nitric Acid Factor: The default is 1.58 calories
per 1000 calories of released energy.
Acid Multiplier: This multiplier is the normality
of the sodium carbonate used during the acid
correction titration. The default value of 0.0709
allows for direct entry of the acid correction
in calories. If the bomb rinses are titrated in
order to determine the acid correction, press
this key to display the Acid Multiplier numeric
dialog box, where you can change the multi-
plier to represent the concentration of the base
(equivalents/L) or normality used for titration.
If this is the case, the acid correction is entered
as milliliters of base used to titrate the bomb
rinses.
Sulfur Value is Percent: When set to ON, the
sulfur value is being entered as weight percent
sulfur. If another system is to be used, this
must be turned OFF and the sulfur multiplier
set accordingly.
Sulfur Multiplier: Values entered by the user to
be used for the sulfur correction are multiplied
by this value to get the product into units of
milliequivalents. The default number (0.6238)
requires that the sulfur value be entered in
weight percent.
Fuse Multiplier: The fuse corrections repre-
sent the number of calories liberated by the
burning fuse wire used to ignite the sample. If
another measurement is used, the correction
factor must be entered here. Press this key to
access the Fuse Multiplier numeric dialog box
and enter this multiplier value.
Use Offset Correction (ISO): The thermochemi-
cal calculations used for treatment of nitric
acid and sulfuric acid corrections in the ISO
and B. S. methods require an offset correc-
tion to compensate for the back titration that
is made. To use these calculations, toggle this
to ON and enter the appropriate value as the
offset value.
Offset Value: The value used when Offset
Correction is turned ON. Press this key to ac-
cess the Offset Value numeric dialog box and
change its value.
Heat of Formation Sulfuric Acid: Different
methods use different values for the heat of
formation of sulfuric acid. The value can be set
to match the specific method being followed.
Default = 36.1.
Heat of Formation Nitric Acid: Different
methods use different values for the heat of
formation of nitric acid. The value can be set
to match the specific method being followed.
Default = 14.1.