Matrix Adjustment; General Information On Matrix Adjustment; Carrying Out The Matrix Adjustment - Xylem YSI VARiON Plus 700 IQ H Operating Manual

Matrix adjustment, check and calibration
Main steps
Online help
Matrix adjustment with
zeroing
Practical instructions
30
4.2

Matrix adjustment

4.2.1 General information on matrix adjustment

This procedure adjusts the value measured directly in the test sample
to an independently determined reference value ("lab value"). To deter-
mine the reference values, a sample is taken from the measuring solu-
tion and the relevant concentrations are measured (e.g.
photometrically).
First select for which of the installed electrodes the matrix adjustment
should be carried out. Based on this selection and the electrode equip-
ment, the sensor software determines the ion types for which a refer-
ence measurement must be carried out. The menu guided routine
adapts itself correspondingly and informs you of all necessary actions.

4.2.2 Carrying out the matrix adjustment

Prior to the matrix adjustment, check the chloride electrode
for coatings and polish it as necessary (see section 6.4).
Step 1: Determination of all electrode voltages ("reference volt-
ages"). The sensor is in the sample.
The procedure is started from the measured value display
with <C>. After completion the system returns to the mea-
sured value display.
Step 2: Sampling at the same place and time if possible and
determination of all relevant reference values
Step 3: Entry and storage of the measured reference values.
This step is started by pressing <C> again.
A convenient, menu guided routine guides you through the
MATRIX ADJUSTMENT procedure. In addition, you can call up an
Online help with <C> for each step. An info box with detailed informa-
tion on the relevant operating step appears on the display. It provides,
for example, important instructions on how to keep the correct basic
conditions. When <OK> is pressed, the display returns to the current
operating step.
After installing a new or different electrode you have to zero the elec-
trode to facilitate a long-term evaluation. Details on zeroing, see
section 4.1.
 Ammonium and nitrate have to be determined immediately after tak-
ing the sample as the their content changes very quickly due to the
micro organisms that are present.It is best to take the sample imme-
®Plus
VARiON 700 IQ H
ba76207e02 12/2020