Xylem 6-Series Multiparameter - Manual (Page 129)

Sondes Section 2
YSI Incorporated Environmental Monitoring Systems Operations Manual 2-123
ROX OPTICAL DISSOLVED OXYGEN
When the 6150 sensor is not in field use, it MUST BE STORED IN A MOIST ENVIRONMENT, i.e.,
either in water or in water-saturated air with storage in water being preferable. If the sensor membrane is
allowed to dry out by exposure to ambient air, it is likely to drift slightly at the beginning of your next
deployment unless it is rehydrated. Thus, to make the use of the sensor as simple as possible, remember to
store it WET whenever possible. The easiest storage method is to use the protective plastic cap (and
enclosed sponge) which was on the probe at receipt. If you have retained this cap/sponge, then simply
soak the sponge in water and replace the cap on the probe tip. Inspect the sponge every 30 days to make
sure it is still moist. Alternatively, you can remove the probe from the sonde and place it directly in water
(making sure that the water does not evaporate over time or leave the probe in the sonde and make certain
that the calibration cup has an atmosphere which is water-saturated by placing approximately ½ inch of
water in the bottom of the cup and then sealing it snugly to the sonde.
pH
The key to pH probe storage, 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 the sensor in commercial pH buffers or
tap water 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 all YSI 6-series sondes other than the 600R and 600QS, 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, or pH 4 or 7 buffer. Make certain that the vessel
is sealed to prevent evaporation of the storage solution.
For YSI 600R and 600QS sondes, remove the reference module and plug the open port with the provided
insert. 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 that must remain in the sonde.
ORP
Long Term Storage: ORP is not available on the YSI 600R. For the 600QS, where the ORP sensor cannot
be removed from the sonde, store the sensor in tap water in a sealed storage bottle. For all other YSI 6-
series sondes, 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.