YSI 6000UPG - Manual (Page 162)

G-4
DISSOLVED OXYGEN
Rapid Pulse dissolved oxygen sensors should always be stored with a membrane and electrolyte in
place and in such a way that the drying out of the electrolyte on the probe face is minimized. For
long term storage, the medium should be water rather than the moist air used in interim storage.
The long term storage protocol is also dependent on the instrument under consideration.
For the 6000 UPG , the 600XL, and the 6820, two long term storage methods are equally acceptable.
❏ Remove all probes other than dissolved oxygen, conductivity, and temperature from the sonde
and seal the vacant ports with the provided plugs. Leave the electrolyte and membrane in
place on the dissolved oxygen sensor. Fill the provided storage vessel with water (tap,
deionized, or distilled are equally acceptable) and insert the sonde. Make certain the water
level is high enough to completely cover the DO sensor. Seal the vessel to prevent evaporation
of the water. At the end of the storage time, remove the existing membrane and remembrane
the probe using new electrolyte.
❏ Remove the dissolved oxygen sensor from the sonde leaving the electrolyte and membrane in
place. Store the probes in water (tap, deionized, or distilled are equally acceptable) in a
beaker, flask, or other vessel of the user’s choice. Be sure not to damage the membrane or the
probe tip when placing the probe on the bottom of the vessel. If possible cover the vessel with
parafilm or plastic wrap to minimize evaporation of the water during the long term storage.
Monitor the water level in the storage vessel periodically and replenish if loss due to
evaporation occurs. At the end of the storage time, remove the existing membrane and
remembrane the probe using new electrolyte.
Because the dissolved oxygen probe associated with the Model 600 cannot be removed from the
sonde by the user, a slightly different long term storage protocol is required:
❏ For 600 systems equipped with a replaceable reference electrode module, remove the reference
module, store it as described below, and plug the open port with the insert which was
provided. Make certain that the dissolved oxygen sensor has an undamaged membrane and
electrolyte in place. Fill the provided storage vessel with a solution which is 2 molar (2 M) in
potassium chloride (KCl), insert the sonde, and seal the vessel with the cap and O-ring. This
solution can be prepared by dissolving 74.6 g of KCl in 500 mL (approximately 1 pint) of
water or 37.3 g of KCl in 250 mL (approximately 0.5 pint) of water. The water should be
distilled or deionized. If KCl solution is unavailable, it is acceptable to store the dissolved
oxygen and pH glass sensors in tap water. However, do not use deionized or distilled water
in this case, as it may damage the pH glass sensor which must remain in the sonde. At
the end of the storage time, remove the existing membrane and remembrane the probe using
new electrolyte.
❏ For 600 systems equipped with a combination pH probe (purchased prior to 1996), none of the
probes are user-replaceable and a different storage technique is required. Make certain that the
dissolved oxygen sensor has an undamaged membrane and electrolyte in place. Fill the
provided storage vessel with a solution which is 2 molar (2 M) in potassium chloride (KCl) to