Metrohm 746 VA Trace Analyzer User Manual

Page 119

4 Introduction to the operation

746 VA Trace Analyzer / 747 VA Stand

4-34

4.3.4

Recording the calibration curve

Recording of the calibration curve involves the following steps:

Switch to dialog page "MONITORING"

•

Press the yellow key. The dialog page "MONITORING"

whose header shows the loaded method

CALCRV

appears.

Switch the program run mode to

calibration

If the parameter

Run mode

is set to

determination

, proceed as follows:

•

Use the cursor keys to select the field

Run mode

•

Press the space bar to enter the edit mode.

•

Press the softkey

and confirm this entry with the

key.

Entry of the sample volume
Enter the sample volume as follows:

•

Use the cursor keys to select the first field below the title

Sample

size/S0

•

Press the space bar to enter the edit mode.

•

Enter either

10 mL

(as preparation for performance of the determi-

nation in section 4.3.5) and confirm this entry with the key.

Although the sample volume for recording the calibration curve is not needed (the
volume of the calibration solutions is defined in the parameter V0.CSoln), the
Sample size/S0 field must not be empty.

Start the determination

•

Press the red key.

•

The status display in the header of the dialog page "MONITORING"

switches to

* BUSY *

, the start time of the measurement is entered un-

der

Determination

and the determination is given a standard name,

also formed from the start time. Further, during the measurement the

measurement window is superimposed which shows the current pro-

gram line being executed and the remaining line time.

•

Shortly after the start of the determination, the prompt to add 10 mL of

calibration solution

Pb-1

to the measuring vessel appears on the

screen:

Addition of 1

calibration solution

•

Remove stopper 25

25 and use a pipette to add 10 mL of calibration

solution

Pb-1

with a mass concentration of 2.5

µµg/L to the measuring

vessel through the pipetting opening. Press the key.

•

The screen shows the prompt to add 1 mL acetate buffer to the measur-

ing vessel:

ЪДДД

ДДД MEAS.TASK MESSAGE ДДДДДДДДДДДДДДДДДД

ДДДДДДДДДДДДДДДДДД¿

CSOLN Pb-1 10.000 mL > M

АДДД

ДДД : continue ДДДДДДДДДДДДДДДДДД

ДДДДДДДДДДДДДДДДДДЩ