Do/Ec Electrode Calibration And Maintenance; Recognising The Do/Ec Electrode; Do Measurement Technique; Precautions During Use - palintest Macro 900 Operation Manual

Macro 900 Operation Manual

14. DO/EC Electrode Calibration and Maintenance

14.1. Recognising the DO/EC Electrode

The DO/EC electrode is easy to recognise because it has a screw-on cap and
four stainless-steel EC sensor contacts on the side (see photograph in section
12). Dissolved Oxygen (DO) is measured at the end of the electrode by the
components behind the removable cap. Electrical Conductivity (EC) is measured
on the side of the electrode by the four stainless steel contacts.

14.2. DO Measurement Technique

The MAP 2000/2100 features an optical DO sensor. This sensor does not use a
liquid electrolyte and has a black rubber gas-permeable membrane. See
Appendix 1. The Tech Behind Palintest's Optical DO Measurement System
further details.

14.3. Precautions During Use

EC measurement is not possible with the Probe sleeve removed as the
sleeve forms an integral part of the measurement system.
Never immerse the Probe without the DO Cap fitted. If the components
at the end of the DO/EC electrode come into contact with the liquid
being tested, serious damage can occur to the DO/EC electrode
circuitry.

14.4. Calibrating the DO/EC Electrode

Calibration of the EC section of the electrode is normally carried out during
MacroCal (see MacroCal Calibration
using different EC Calibration Standards, this is covered after the DO calibration
section (Calibrating
The DO section of the electrode should be calibrated at the Zero saturation
point at least once a month. Before each day's use, the 100% saturation point
should be checked in moist air and re-calibrated if necessary. For optimum
accuracy, calibrate the DO100% point as near to your sample temperature as
possible (within the calibration temperature limits of 5°C - 40°C).
If you are going to calibrate both the Zero and 100% points at the same time,
ALWAYS calibrate the Zero point first, then the 100% point.

14.5. Calibrating the DO Zero Point

1. Remove the lid from a 150mL bottle of DO Zero calibration solution,
remove the storage cap from the pH electrode if fitted, wash the Probe in
distilled water, then drop the Probe in all the way.
2. Switch the Macro 900 Meter on and wait until the DO reading is
completely stable.
3. Ensure the temperature of the solution is between 5
-
4. Press the MENU key then select Calibration. The following screen will
© 2013 Palintest Ltd.
EC).
www.palintest.com
Method). EC can be calibrated separately
V3
for
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