7 calibration curve technique – Metrohm 757 VA Computrace User Manual

Page 160

7 How to ...?

757 VA Computrace – Software

150

7.7

Calibration curve technique

Record calibration curve manually by adding standard solution

This method is used for preparing different calibration solutions
by adding several times a concentrated standard solution to the
measuring solution using a pipette. Proceed as follows:

1. Click on

MAIN WINDOW

/ Mode / Determination

2. Click on

MAIN WINDOW

/ Window / Working method

specification

to open the

WORKING METHOD SPECIFICATIONS

window.

3. Load the desired method into the

WORKING METHOD SPECIFI-

CATIONS

window (see How to load a method).

4. Select

Record calibration curve

in the

Calibration

field of the

WORKING METHOD SPECIFICATIONS

window.

5. Select

Manual

in the

Addition

field of the

WORKING METHOD

SPECIFICATIONS

window.

6. Select

Batch

in the

Technique

field of the

WORKING METHOD

SPECIFICATIONS

window.

7. Click

to open the

EDIT WORKING METHOD PA-

RAMETERS

window.

8. Select the

Determination

tab (see section 5.2) and enter the

Cell volume

and the number of additions in the

No. of additions

field.

9. Select the

Substances

tab (see section 5.2) and make sure

that for each substance entered in the table the number of the
single or mixed standard solution, its concentration and its
volume is defined.

10. If the addition of the standard solution should be done with

variable addition volumes, click the button in the

Volume

column to open the

EDIT VARIED ADDITION

window, enter the

variable addition volumes in the

Addition

fields, and close this

window by clicking

11. Close the

EDIT WORKING METHOD PARAMETERS

window by

clicking

12. Place the electrolyte solution (e.g. buffer) in the measuring

vessel at the 757 VA Computrace Stand.

13. Click on

MAIN WINDOW

/ Window / Monitor

to open the

MONITOR

window.

14. Start the measurement by clicking the

icon in the

MAIN

WINDOW

or the

button in the

MONITORING

window.