YSI 6000UPG - Manual (Page 163)

G-5
a level which completely covers the dissolved oxygen and pH probes. Seal the vessel with the
cap and O-ring. At the end of the storage time, remove the existing membrane and
remembrane the probe using new electrolyte.
pH
The key to pH probe storage, either short or long term, is to make certain that the reference
electrode junction does not dry out. Junctions which have been allowed to dry out due to
improper storage procedures can usually be rehydrated by soaking the sensor for several hours
(overnight is recommended) in a solution which is 2 molar in potassium chloride (see dissolved
oxygen section above for preparation of this solution). If potassium chloride solution is not
available, soaking in tap water or commercial pH buffers may restore probe function. However in
some cases the sensor may have been irreparably damaged by the dehydration and will require
replacement. It is also important to remember not to store the pH sensor in distilled or deionized
water as the glass sensor may be damaged by exposure to this medium.
The long term storage protocol is dependent on the instrument.
For Model 6000 UPG , 600XL, and 6820 systems, the recommended long term storage protocol is
identical. Remove the probe from the sonde and seal the vacant port with the provided plug. Place
the probe in the storage vessel (plastic boot or bottle) which was in place on delivery. The vessel
should contain a solution which is 2 molar in potassium chloride. Make certain that the vessel is
sealed to prevent evaporation of the storage solution. Electrical tape can be used to provide a
removable seal between the boot and the module body.
For Model 600 systems equipped with a replaceable reference electrode module, remove the
reference module and plug the open port with the insert which was provided. Place the module in
the storage vessel boot which was in place on delivery and seal the vessel with electrical tape. The
vessel should contain a solution which is 2 molar in potassium chloride and should be sealed to
prevent evaporation of the storage solution. Make certain that the dissolved oxygen sensor has an
undamaged membrane and electrolyte in place. Fill the provided sonde storage vessel with tap
water, insert the sonde, and seal the vessel with the cap and O-ring. Do not use deionized or
distilled water in this case, as it may damage the pH glass sensor which must remain in the
sonde.
For Model 600 systems equipped with a combination pH probe (purchased prior to 1996), 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 in potassium chloride (KCl) to a level which completely covers the dissolved
oxygen and pH probes, insert the sonde, and seal the vessel with the cap and O-ring.