Oxygen Measurement - Consort C832 Anleitung

(C835)
Maintenance:
After prolonged use of the electrode the internal electrodes may become deacti-
vated by undesired deposits. An indication is that the electrode no longer responds
correctly to calibration. In this case:
1. Carefully screw off the measuring head.
2. Cautiously remove the precipitated deposits with the aid of filter paper. Do
not use grinding paper or a glass fibre!
3. Rinse several times with distilled water and shake carefully off the water
drops.
4. Take the measuring head, fill it with new electrolyte solution and very slowly
screw it onto the electrode while holding it vertically. Take care that no air
bubbles are present in the measuring head!
5. Let the electrode rest for a few hours! The electrode is now ready for use
again.
• Replace the membrane only when damaged, not when calibration is no longer
possible!
Measurement:
1. Select the mg/l (mg/l) or % range. The display will immediately show the
measured oxygen according to the previous calibration. Should you want to
recalibrate, press CAL.
2. The display shows [SAL= MAn] (manual salinity correction) or [SAL= Aut] (auto-
matic salinity correction). Choose the desired mode and press CAL. If you
choose [SAL= MAn] the display will show, e.g. [SAL=21]. Leave this value to
zero unless you are going to measure in heavily salted solutions such as e.g.
sea-water (35). Pre-set the proper value and press CAL.
3. The display shows the pressure correction, e.g. [P=1023hP]. Pre-set the actual
air pressure (hP) and press CAL.
4. The electrode exposed to the air reaches an equilibrium corresponding to the
partial pressure of oxygen and thus to saturation in water at the given tem-
perature. The instrument shows the measured saturation, e.g. [SAt=8.3] and
will calibrate automatically when readings are stable ([=] stops blinking).
5. After rinsing the electrodes with distilled water, immerse them in the samples
and read the display. The advection rate must be at least 10 cm/s (stir!).
6. Rinse the electrode always after use and store it in distilled water.
• Press RES to change the resolution from 0.1 to 0.01 mg/l or from 1 to 0.1 %.
Relative O measurement:
2
1. While in the O
range, press Ù. At that moment the instrument stores the
2
actual value and automatically subtracts it from all next measurements.
You can repeat this as many times as required. A blinking [r] in the display
appears.
2. To cancel relative readings, press MODE and you will be in the normal measur-
ing mode again.
C831 • C832 • C833 • C835 • C838

Oxygen measurement

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