Making Sensors Work Underwater

Fred DonelsonKevin McKone

Why Have Sensors?

Study Wildlife

Investigate Archeological Finds

Monitor/Evaluate Equipment

Map the Sea Floor

Study Climate/Circulation Effects

There are LOTS of types of Sensors!

• Temperature• Pressure• Dissolved O2

• Dissolved CO2

• Various types of salts• Conductivity• And many, many more …

So let’s hook one up to our ROV!

Here’s the Big Picture:

We want to make a sensor connector that will• be powered by our laptop USB port or

controller card• easily hook up to several different types of

Vernier probes• enable users to quickly swap out tools/probes

during or after a work session

Here is the basic idea:

Wires come from computer CAT5 on left

and go to sensor on right

Here We’ve Opened the Connector

Opening the connector reveals wires with snap connectors

Unsnap the Connectorsto Make a Swap!

Some of the basic parts we need:

We will also need:

• Plumbers putty• PVC primer and cement• A hot plate or pan that can be made into a

double boiler• A beaker or container in which to melt wax• A six terminal barrier strip

Let’s start with a Vernier surface temperature probe

First, Cut the Wire in Half and Strip Back the Outer Shield

Here are 3 different sensors:Notice they all have six wires, making

them interchangeable!

Now, Let’s Put the Parts Together!

Drill a hole in both end caps just large enough for the probe wires

Next, cut two pieces of 1” PVC pipe

Each one should be around 12 cm long

Now obtain some PVCprimer and cement

Prime the end of the PVC pipes and the inside of the adaptors

Then apply PVC cement and push them together

You should now have both halves together (both male and female ends)

Next, thread the probe wire through the end cap so that the

wires come out the female adapter

Be sure you use the female side!

Use some clay or plumbers putty to plug the hole on the end cap side

Place the tube clay-side downin a container

Melt some wax until liquid and pour into the open end, filling the tube

approximately ½ full

Remember: Hot wax

isHOT!!

Repeat the process on the male end with the CAT5 cable

Add the clay …

Pour the wax and let cool and solidify

Now to add the snap

connectors ...

Double the wire, slide into the connector, and then clamp on with

pliers or other clamping tool

Be sure to put the male ends on the male adapter end of the tube

Attach the female connectors to the probe end (female adaptor side)

Use a six-terminal barrier strip to connect the top of the

CAT5 to the computer side of the wire for

the probe

Connect the computer end of the probe (left) to your CAT 5 wire in your tether (on the right). You only need 6 wires.

Here’s a close up view. Remember the order so you can connect the wires the

same way in your connector

Now connect the correct CAT5 wires to the sensor probe wires in the same way

Next, grab some plumbers putty

Place the putty around the male adaptor, then screw two ends together

The finished product should look something like this!

Now to hook it all together …

First, the Go-Link to the USB port:

Then the computer/CAT5 end of the probe to the Go-Link:

Go-Link on left … CAT5 on right

Through the CAT5 wire in our teather …

And finally to the connector and probe

Then, be sure and place in some water and test for a few hours!

Sample graph with probe put near a block of ice in the water at about 40 seconds

Now … go measure something!!