Through Hull Speed/Depth Transducer - How Do You Clean?

[Cruisin Cat]

I have a Furuno Speed/Depth instrument with a retractable Airmar Speed/Depth/Temp transducer fitted in the hull.

The depth function on this transducer has just failed....giving some rapidly changing and very incorrect depth figures. It's about 2 years old.

Through its 2 year life, I have pulled it out of the hull and cleaned it with vinegar when it got barnacle growth on it. Could this damage the transducer?

The other possible cause of damage is that I have on occassion left the transducer running when pulled out of the hull, ie depth transducer emitting its ultrasonic pulse into air instead of into water. Would this damage the depth transducer?

Hope to hear from people who have had some similar experience so I can figure out how to stop the next one failing in 2 years

[Jim Cate]

G'Day CC,

No specific experience with Furuno instruments, but with other Airmar transducers I have duplicated your practice with no ill effects. Vinegar does a great job of removing shelly growth where you can't get at it, and running the d/s in air will not cause any problems.

If you haven't already done so, check the cable and connectors... these often give problems.

Cheers,

Jim

[daddle]

Yeah, probably the connector. Or the wire got smashed somewhere. Depth transducers are very rugged: basically a solid chunk some trick rock.

[Wotname]

You should only have one connector in this system (on the back of the Furuno Speed/Depth instrument). As others have said, check it and make sure wiring loom hasn't been squashed or kinked somewhere. Other than that, either the the Furuno or the transducer is failing.

Your maintenance & handling of the transducer is very unlikely to have caused the problem.

It there any possibility of the water ingress to the Furuno unit?

[GordMay]

From Airmar instructions ➥ Airmar FAQ - What should I use to clean my transducer?

Never use solvents. Cleaners, fuel, sealants, paint, and other products may contain strong solvents, such as acetone, which attack many plastics, greatly reducing their strength.

Aquatic growth can accumulate rapidly on the transducer’s surface reducing its performance within weeks.
Clean the surface with a Scotch-Brite® scour pad and mild household detergent taking care to avoid making scratches.
If the fouling is severe, lightly wet sand with fine grade wet/dry paper.

[Cruisin Cat]

Thanks everyone for your comments.

A bit more info to answer some of the questions....the transducer I have is what AIRMAR calls a SMART TRI MULTISENSOR. As the name implies it has 3 transducers in one retractable through hull device....DEPTH, SPEED & WATER TEMP.

The smart part means that it has some electronics in the transducer so that instead of having separate screened cable pairs connected to each function, it has a single cable with a screen and 4 wires in it.....2 are for +ve and -ve power supply and the other 2 are to transmit all data. The electronics in the transducer presumably receives DEPTH, SPEED & WATER TEMP information continuously then packages it in some format (NEMA 2000 I think) and sends it down the 2 data wires periodically with an identifier so the instruments receiving the data know if it is speed, depth or water temp..
I thought about the bad connection possibility but then discounted it because the speed display is ok and that data is coming down the same 2 wires as the depth data….so I figured it must be in the transducer itself.

[Cruisin Cat]

Thanks everyone for your comments.

A bit more info to answer some of the questions....the transducer I have is what AIRMAR calls a SMART TRI MULTISENSOR. As the name implies it has 3 transducers in one retractable through hull device....DEPTH, SPEED & WATER TEMP.

The smart part means that it has some electronics in the transducer so that instead of having separate screened cable pairs connected to each function, it has a single cable with a screen and 4 wires in it.....2 are for +ve and -ve power supply and the other 2 are to transmit all data. The electronics in the transducer presumably receives DEPTH, SPEED & WATER TEMP information continuously then packages it in some format (NEMA 2000 I think) and sends it down the 2 data wires periodically with an identifier so the instruments receiving the data know if it is speed, depth or water temp..

I thought about the bad connection possibility but then discounted it because the speed display is ok and that data is coming down the same 2 wires as the depth data….so I figured it must be in the transducer itself.

[Ex-Calif]

Originally Posted by Cruisin Cat

I have a Furuno Speed/Depth instrument with a retractable Airmar Speed/Depth/Temp transducer fitted in the hull.

The depth function on this transducer has just failed....giving some rapidly changing and very incorrect depth figures. It's about 2 years old.

Through its 2 year life, I have pulled it out of the hull and cleaned it with vinegar when it got barnacle growth on it. Could this damage the transducer?

The other possible cause of damage is that I have on occassion left the transducer running when pulled out of the hull, ie depth transducer emitting its ultrasonic pulse into air instead of into water. Would this damage the depth transducer?

Hope to hear from people who have had some similar experience so I can figure out how to stop the next one failing in 2 years

Several people have reported fluctuating readings at berth in Marinas (not specific to Furuno)

Once in a while mine will jump from 17 meters to 2 meters and then 30 seconds later be normal again although never in my berth.

I clean my speed log wheel but have never specifically cleaned the depth transducer. Just gets wiped over when the hull is cleaned.

[chala]

Originally Posted by Cruisin Cat

The other possible cause of damage is that I have on occassion left the transducer running when pulled out of the hull, ie depth transducer emitting its ultrasonic pulse into air instead of into water. Would this damage the depth transducer?

Depending on the power rating of the transducer the following warning apply.

Warning: Sonar operation
• NEVER operate the sounder with the boat out of
the water.
• NEVER touch the transducer face when the sounder
is powered on.
• SWITCH OFF the sounder if divers are likely to be
within 25 ft (5 m) of the transducer.

[Jim Cate]

Originally Posted by chala

Depending on the power rating of the transducer the following warning apply.

Warning: Sonar operation
• NEVER operate the sounder with the boat out of
the water.
• NEVER touch the transducer face when the sounder
is powered on.
• SWITCH OFF the sounder if divers are likely to be
within 25 ft (5 m) of the transducer.

Chala, could you please give us the source of this info?

Having routinely disobeyed all three warnings with no apparent damage to me or a variety of depthsounders, I'm a bit curious.

Have to wonder if the above warnings are related to far more powerful units that a typical yottie job.

Cheers,

Jim

[chala]

Jim
The warnings come with the following displays installation manuals.

e7D / e97 / e127/c97 / c127 displays only
(Internal sonar specification
Operating frequencies 50 / 83 / 200 KHz
Transmit power Up to 600 W RMS, depending on
transducer
Depth range Up to 3000 ft, depending on transducer),

E90W, E120W and E140W models,

and also with the C90W, C120W and C140W models. (Pods and DSM)

May also apply to A50, A50D, A57D, A70 and A70D models
Used with DSM 300 transducers B117, P319, P79, B258, B744VL

No specific warning on Airmar install P319 transducer if it is: “2. Refer to the echosounder owner’s manual to connect the transducer to the instrument.”

From manual:
• Always check the installation before going to sea to make sure that it
is not affected by radio transmissions, engine starting etc..
• In some installations, it may not be possible to prevent the equipment from being affected by external influences. In general this will not damage the equipment but can lead to it resetting, or
momentarily may result in faulty operation.

Typical used to be yottie job.

ST80 Active Depth Transducer
Depth range: 1.5 to 600ft (200ft at 25 knots)
and 600ft at 5 knots.
Power consumption: 50 mA
Power supply: 10 to 16V
Transmitted power: 50W RMS

[Cruisin Cat]

Originally Posted by Cruisin Cat

I have a Furuno Speed/Depth instrument with a retractable Airmar Speed/Depth/Temp transducer fitted in the hull.

The depth function on this transducer has just failed....giving some rapidly changing and very incorrect depth figures. It's about 2 years old.

Through its 2 year life, I have pulled it out of the hull and cleaned it with vinegar when it got barnacle growth on it. Could this damage the transducer?

The other possible cause of damage is that I have on occassion left the transducer running when pulled out of the hull, ie depth transducer emitting its ultrasonic pulse into air instead of into water. Would this damage the depth transducer?

Hope to hear from people who have had some similar experience so I can figure out how to stop the next one failing in 2 years

Thanks everyone for your comments.

I have installed a new transducer and it's working fine now.