The document details the history and development of YSI's Exo sonde line, which was introduced in 2012 to enhance multi-parameter monitoring capabilities through advanced technology and design. It emphasizes the importance of reducing biofouling, extending deployment times, and improving data quality, leading to lower operational costs. Key materials and methods for protecting and maintaining the sonde's sensors are also provided to ensure long-term monitoring success.

1. Making The
Switch To EXO
How to extend your
deployment times
Mike Lizotte

2. YSI Sonde History
• In 1994 YSI introduced its first multiparameter sonde the Model
6000, this platform introduced the first flow independent, and
patented, DO sensor to the multi-parameter sonde market place
• In 1998 YSI we upgraded this platform and introduced the Model
6600 multi-parameter sonde
• Other products followed including the 6600 EDS which used a
patented brush anti-fouling system, and the last addition in the
6600V2-4 which gave our customers maximum application and
deployment flexibility

3. Sonde History cont.
• Over the years in all these platforms we gathered data from our
customers and their applications and learned what they liked and
what they wanted improved
• In 2012 it was time to show our customers that we had listened and
we introduced the EXO sonde line to the market place.
• This product line which was 3 years in the making completely
redefined what a multi-parameter sonde should be and how it
should work

4. EXO: What did we change?
• The short answer is EVERYTHING – The 6-Series product line was a
workhorse and over the years we made many changes, options, and
improvements to these platforms. However, at some point there
comes a time when advances in electronics, technology and the
lessons learned make it necessary to start over and build a new
product that will serve our customers for many years to come
• EXO is the culmination of 18 years worth of our sonde building
experience combined with the latest advances in materials and
electronics technology

5. EXO Design Goals
• Reduce calibration costs, labor and materials
• Reduce servicing requirements
• Extend deployments for long term monitoring and DCP (data
collection platform) studies
• More accurate sensors for higher data quality
• Smart QC with automatic calibration and meta data generation
• Improve Anti-Fouling capabilities for all sensors
• Data must be compatible with legacy 6-Series data

6. Fouling “The Enemy”
• In most deployments biofouling of the sensors is the reason water
quality instruments cannot be deployed indefinitely
• Advances in technology, improved durability and the drift free
nature of sensors like optical DO have now made long term
deployments possible if the sensors can be kept clean
• Fouling has many forms, whether fresh water or marine, most
locations have some form of fouling that must be kept at bay if we
are to have high quality data

7. Example 1:
6600 in a 30 day study
• Biofouling on wiper shafts,
edges of sensors pH probe, and
CT sensor
• At first glance because the
optics are clear you would think
that this data would be good
• What fouling looks like in water
vs. out can be quite different

8. Example 2:
6600 later in season, 50 day study
• Picture shows much cleaner
sensors, some growth attached
to the wiper shafts
• This again looks like minimal
fouling and not a threat to the
optical data
• But placing the sonde back in
water shows a very different
situation…

9. Wiper Shaft: Fouling in Water
• The small growth on the end of
the wiper shafts fans out when
in water
• Currents and flow will make
this growth move back and
fourth in front of the optics
• The result is offsets, spikes,
and interference in the
measurements

10. Biofouling
caused
effects on
sensors

11. EXO 2 Sonde at Example 1 Site
• Sensors perfectly clean even
after 30 days insitu
• Throughout the EXO
development program the
central wiper with its garage
and copper alloy wiper arm
demonstrated superior
cleaning capabilities in all
tested environments

12. Summary
• The EXO2 with its central wiper
and YSI recommended AFcomponents is the most fouling
resistant sonde you can deploy
• These benefits translates into
longer deployment times, less
trips to the field for servicing,
and higher data quality all of
which contribute to lower
operating costs

13. Getting Started
Basic Materials
• Duck Brand or Scotch 2 inch
wide clear packing tape
• High visibility Duck Tape
• # 11 Xacto knife and blades
• Sharp scissors
• YSI 2 inch wide copper tape
(p/n 616189)
• Black indelible ink Sharpie
• C-Spray YSI (p/n 616290)
• CT anti-fouling screen (not
shown) (p/n 599867)

14. Materials: What do they do?
• The clear packing tape is installed so that removal of the copper tape
(when expired) is much easier, this can be substituted by the YSI shrink
wrap sleeves
• Copper Tape provides the fouling protection
• Duck brand duct tape has demonstrated an ability to reduce fouling in
marine environments. If it should foul it can be removed from the sonde
with minimal effort
• C-Spray is used to make removal of fouling easier from parts of the sonde
that are can’t be taped
• AF-Screen provides protection to the conductivity cells

15. How long does the copper last?
• The full treatment as shown will
last 2 to 3 months before
replacement is needed in warm
marine waters, longer in less
saline conditions
• The CT anti-fouling screen will
need cleaning more frequently

16. Sensor Removal and Cleaning
• Clean sensors of any fouling
and dry
• Ensure that the inside of the
conductivity cells are also clean
• Wash with dishwashing soap
and warm water
• Soak in white vinegar for more
aggressive cleaning

17. Example 1 – CT Probe
• Remove one of the antifouling screens from the
package and position so that
the seam is not over either of
the two side vents
• Do not allow top edge of
screen to protrude above the
temperature probe ledge

18. Clear Tape Application
• Tear off a length of clear
packing tape so that the main
body of the probe up to the
screen is covered
• Square up the tape by eye so
that when it is rolled in place it
is smooth and not crinkled

19. Copper Tape Application
• Measure out and cut a long piece
of copper tape
• Square this edge up to the base of
the sensor
• The length should go up and over
the CT screen to hold it in place
• Carefully roll the probe to apply
copper and using the Sharpie
press out any wrinkles

20. Finished CT Sensor
• Note: position of seam, away
from vent
• Note: top edge of screen does
not protrude above flat
temperature probe shelf
• If needed apply additional
copper tape to close any gaps
or spaces

21. Example 2 – pH Sensor
• pH, DO, and the optical sensors
are all protected the same way
• Cut a 4.6 inch length of the clear
2” wide packing tape and square it
up to ~1/16 of an inch below the
end at the bulb
• Wrap the tape around the probe,
keeping wrinkles to a minimum

22. EXO Sensor Wraps
• The YSI sensor shrink wrap is
another option for under the
copper tape
• Use extreme care when shrinking
the wrap, do not use a flame or
heat gun with high output
• Align at top, cut excess away at
locking nut end

23. Removing Excess with a Knife
Always use caution
when handling a
Xacto blade.

24. Starting the Wrap
• Square up a 4/.6 inch long piece of
copper tape to within 1/16 of an
inch from bulb end
• Press firmly and begin wrapping
the sensor
• Using the Sharpie roll out all
wrinkles and make smooth
• If a gap exists patch it

25. Example 3 – Wiper Housing
• Do not remove the Parking Garage!
• Cut three 3.5” lengths of clear
packing tape
• Starting below the garage wrap the
tape neatly around the body.
• Overwrap the second piece
• Wrap above garage and trim to fit
with knife

26. Applying the Copper
• Cut three 3.5” lengths of copper
tape
• Start below the garage with the first
strip
• Overlap so that second piece is
square to the bottom of the
housing
• Roll out all wrinkles with the
Sharpie and close any gaps

27. Finishing the Copper
• Fit last piece of copper
• Cut to complete wrap around
• Roll out all wrinkles with the
Sharpie and close any gaps

28. Setscrew
• Grease the setscrew quarterly

29. Bulkhead
• Clean endcap as needed, use
scouring pad or mildly abrasive
sponge
• Dry excess moisture from
threads and face
• Spray with C-Spray to aid in
future cleanup

30. Installing the Wiper and Sensor
Grease
M&F pins
also
• Apply a dap of Krytox grease
onto the threads of each probe
and the wiper
• Also lightly grease the male,
female pins, and base, unlike 6Series wet pluggable connectors
want to be lubricated
• Do this 4 times a year

31. Finished Sensor Installation
• Date is written on sensors
• Apply a second coat of C-Spray
onto the sensor bulkhead and
probe retaining nuts, let air dry
if possible

32. Why protect the sonde body?
• Two sondes deployed for 4 weeks
in Tampa bay
• Top sonde did not have Duck Tape
protective covering, but bottom
sonde does
• Upper sonde had 1 inch thick
barnacle growth around entire
diameter
• Taped sonde, minimal growth
much easier to clean

33. How to protect sonde body?
• Arrow points to 2 layers of clear
Duck clear tape which has been
applied over the sondes label
• This allows user to see magnet
location and LED’s to confirm
Bluetooth status
• No protection (tape) will
eventually result in a damaged
and illegible label

34. Protection cont.
• Instead of the clear tape you can
also use the EXO2 sonde sleeve
• High visibility green Duck tape also
provides abrasion and AF
protection
• This tape is available in other
colors including camouflage

35. Why you need an
Antifouling Guard
• This is the interior of the stock
plastic guard after 2 weeks in a
productive marine site
• This growth like the growth on
the 6-Series wiper shafts will
affect optical sensor data and
must be prevented
• The AF Guard does this!

36. Greasing Wet
Mateable Connectors
• Shown is a “Vented Level” EXO2
sonde connector
• Krytox grease has been applied
to the rubber around the male
pins including the vented center
pin
• Do not allow grease to seal the
open vented pin!

37. Last Step
• The vented cable has been
plugged in and the locking
sleeve hand tightened to secure
• Same procedure for non-vented
cables and dummy plugs
• Spray connector, dummy plugs,
battery and compartment cover
with C-Spray to aid in cleaning

38. Final Thoughts
• These steps are key to long term deployments and quality data
• With protected sensors, AF guard, sonde body and the EXO2’s
superior Central Wiper system the EXO2 is capable of very long
deployments which translate into lower data and program costs.
• We hope that you have found this information useful and that it
aids your program
• See our Installations and Mounting presentation for additional
useful tips and applications information