Making The Switch To EXO

Mike Lizotte

How to extend your deployment times

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

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

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

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

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

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

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…

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

Biofouling caused

effects on sensors

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

Summary

• The EXO2 with its central wiper and YSI recommended AF-components 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

Basic Materials

Getting Started

• 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)

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

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

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

Example 1 – CT Probe

• Remove one of the anti-fouling 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

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

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

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

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

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

Removing Excess with a Knife

Always use caution when handling a Xacto blade.

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

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

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

Finishing the Copper

• Fit last piece of copper

• Cut to complete wrap around • Roll out all wrinkles with the

Sharpie and close any gaps

Setscrew

• Grease the setscrew quarterly

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

Grease M&F pins

also

Installing the Wiper and Sensor

• 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 6-Series wet pluggable connectors want to be lubricated

• Do this 4 times a year

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

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

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

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

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!

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!

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

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