Metrohm 761 SD Compact IC - Manual (Page 90)

5 Operation
761 SD Compact IC / Instructions for Use 8. 761.1043
82
5.1.2.2 Calibration and sample determination (manual operation / «IC
Cap»)
The instrument should be calibrated after each restart.
The sample aspirating tubing 3 should be immersed in the PE bottle
(6.1608.080) filled with ultra-pure water after each sample (or stan-
dard).
1 Set system manual.smt
⇒ Click on the yellow <Sample> button at the top right so that
it changes to the green <Start> button.
⇒ Choose system manual.smt for item System .
2 Calibration
⇒ Insert the free (dry) end of the sample aspirating tubing 3 into
the MCAL standard with the lowest concentration (150 mg/L
H
3
PO
4
plus basic content of nitrate and sulfate). The MCAL
standard bottles are supplied as accessories (6.2321.000).
⇒ Choose type "Calib(1)" for item
Run Type
.
⇒ Enter a selection, e.g. "Standard 1" for item Ident .
⇒ Start the determination by clicking on the green but-
ton and allow it to run through to the end.
⇒ After completion of this measurement, you should determine
the other 5 MCAL standards one after the other (250, 350,
450, 550 and 650 mg/L H
3
PO
4
plus basic content of nitrate
and sulfate). When doing this, increase the type in increments
in each case by 1 (Calib(X)) in item
Run Type and adjust the
entry in item Ident (this means that type "Calib(6)" should be
set for the Run Type and “Standard 6” should be set for item
Ident in the above example for measurement with the 650
mg/L standard).
⇒ In order to check calibration, you should also determine the
MCAL QC check standard with 545 mg/L H
3
PO
4
plus basic
content of nitrate and sulfate at the end of the series of cali-
bration measurements. Choose type “Sample” in item Run
Type for this measurement.