Xylem Oxix Calibration - Manual (Page 4)

Item Oxix
Name: FW 846003-001
Release date: 12/07 2011
S/N at release date: 97060 Quick Guide for Oxix
Calibration
Version: 04-2012 KJ
EN 5.4 Oxix Quick guide for calibration 1204.doc 4/7
Span Calibration
A span check or calibration is conducted as follows:
•
The sensor is measuring. The current measurement is shown in line 2 (5.20 mg/l in this
example).
•
Set the desired measuring value on the first line using the up and down arrow keys.
•
Save the current measurement setup by pressing OK.
It is generally difficult to conduct a span calibration. Usually, a reference sensor is used to verify
the measurement. For non-oxygen solutions, a variation of 1 to 5% between two sensors can occur
(even when the sensors are placed right next to each other). Air bubbles on the optical window will
create measurement variations.
Theory on making oxygen saturated solution
An oxygen saturated solution can be made from demineralised water being oxygenated for a
minimum of 30 minutes with atmospheric air. This saturation can then be calculated into an oxygen
concentration.
The temperature of the solution is measured with decimal and the atmospheric pressure is
measured with mm Hg.
The ppm or mg/l value of the saturated solution at the given temperature can then be decided by
using a matrix.
Span Calibration
5.00 mg/l
Oxygen 5.20 mg/l
Set actual measurement
Back Select OK