Hitachi 902 - Electrolyte Concentration Calculation; Calculation of SL (Slope Value); Concentration Calculation of Internal Standard Solution; Calculation of Compensation Value (C.VALUE)

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9.4 Electrolyte Concentration Calculation
An example of Na calculation with use of the printout example on the previous page is
described here.
Calculation of SL (slope value)
SL =
E E
C
C
H L
H
L
−
log
=
− −32 0 39 6)
160
120
. ( .
log
= 60.8
SL : Slope value
E
H
: Electromotive force of HIGH solution (32.0)
E
L
: Electromotive force of LOW solution (-39.6)
C
H
: Concentration of HIGH solution (160.0)
C
L
: Concentration of LOW solution (120.0)
Concentration calculation of internal standard solution
C
IS
= CL
E
I
S
E
L
SL
×
−
10
= 120 0 10
35 4 39 6
60 8
.
. ( . )
.
×
− − −
= 140.7
C
IS
: Concentration of internal standard solution
E
IS
: Electromotive force of internal standard solution (-35.4)
Calculation of compensation value (C.VALUE)
The difference between the input value and measured value is obtained through measurement
of the Hitachi calibrator having the known concentration.
C.VALUE = C
c
- C
x
= 139.0 - 138.9
= 0.1
C
c
: Input value (139.0)
C
x
: Measured value (138.9)