YSI 550 DO, Руководство по эксплуатации

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YSI Incorporated YSI 550 DO Handheld Instrument 8
2. Unscrew and remove the old membrane cap.
3. Thoroughly rinse the sensor tip with distilled or DI water.
4. Prepare the electrolyte according to the directions on the KCl solution bottle.
5. Hold the membrane cap and fill it at least 1/2 full with the electrolyte solution.
6. Screw the membrane cap onto the probe moderately tight. A small amount of electrolyte should
overflow.
7. Screw the probe sensor guard on moderately tight.
CAUTION: Do not touch the membrane surface.
3.5 PROBE OPERATION AND PRECAUTIONS
NOTE: The YSI 550DO Instrument should not be used in a purpose other than that specified by
YSI Incorporated. See Section 7, Warranty and Repair for details.
1. It is important to recognize that oxygen dissolved in the sample is consumed during probe
operation. It is therefore essential that the sample be continuously stirred at the sensor tip. If
stagnation occurs, your readings will be artificially low. Stirring may be accomplished by
mechanically moving the sample around the probe tip, or by rapidly moving the probe through
the sample. The rate of stirring should be at least 1 foot per second.
2. Membrane life depends on usage. Membranes will last a long time if installed properly and
treated with care. Erratic readings are a result of loose, wrinkled, damaged, or fouled
membranes, or from large (more than 1/8" diameter) bubbles in the electrolyte reservoir. If
erratic readings or evidence of membrane damage occurs, you should replace the membrane
and the electrolyte solution. The average replacement interval is two to four weeks.
3. If the membrane is coated with oxygen consuming (e.g. bacteria) or oxygen producing
organisms (e.g. algae), erroneous readings may occur.
4. Chlorine, sulfur dioxide, nitric oxide, and nitrous oxide can affect readings by behaving like
oxygen at the probe. If you suspect erroneous readings, it may be necessary to determine if
these gases are the cause.
5. Avoid any environment that contains substances that may attack the probe materials. Some of
these substances are concentrated acids, caustics, and strong solvents. The probe materials that
come in contact with the sample include FEP Teflon, acrylic plastic, EPR rubber, stainless
steel, epoxy, polyetherimide and the PVC cable covering.
6. For correct probe operation, the gold cathode must always be bright. If it is tarnished (which
can result from contact with certain gases), or plated with silver (which can result from
extended use with a loose or wrinkled membrane), the gold surface must be restored. To
restore the cathode, you may either return the instrument to the factory or clean it using the
sanding disk in the YSI 5238 Probe Reconditioning Kit. Never use chemicals or abrasives not
supplied with this kit.