Metrohm 756 KF Coulometer - Manual (Page 34)

3.5 Mode selection, key <MODE>
756/831 KF Coulometer, Instructions for Use 26
3.5 Mode selection, key <MODE>
The key <MODE> is pressed repeatedly until the
required mode is displayed. This is accepted with
<ENTER>.
The following modes can be selected:
• KFC: coulometric KF titration.
• KFC-B: KF titration with blank value correction
• BLANK: determination of blank value
• GLP: mode for system validation
The newly loaded modes are provided with standard
parameters and immediately ready for use.
The modes differ in their standard calculation formulas,
see following table.
Mode Calculation
formula Remarks
KFC content=H2O*C01/C00/C02;1;ppm
C01=1
C02=1
KFC-B blank=C39;1;ug
content=(H2O-C39)*C01/C00/C02;1;ppm
C01=1
C02=1
C39=blank
BLANK blank=H2O;1;ug C39=MN1
GLP content=H2O/C01/C00;3;mg/g
recovery=RS1/C22;2;
C01=1000
C22=Id2= contents information of reagent
manufacturer
Limit value check for RS2
on
: 1)
Lower limit: 0.97
Upper limit: 1.03
Inquiry of id1 and id2; text:
id1: charge
id2: mg/g H2O
1) The default limits for the recovery rate correspond to the information for the standard with 1000 ppm (1.00 mg/g) water.
For the standard with 100 ug water the limits 0.90 and 1.10 apply.
Operands for C01 and C02 in the modes KFC and KFC-B
Result
in
Sample
size in
C01 C02 Result
in
Sample
size in
C01 C02
ppm
%
mg/g
g
1
1
1
1
10 000
1 000
mg/ml ml 1 1 000
ppm
%
mg/g
mg
1 000
1
1
1
10
1
mg/ml ul 1 1
MODE
;
–
mode
mode: KFC