How do you test a depth transducer?

[DavidGrieves]

Hi
My depth sounder just stopped working today. It has an airmar transducer and a raymarine ST60 tri data display.
the display works but is only showing 3 dashed instead of a reading. I’m suspecting the transducer, is there any way the test it with a multi meter?
Regards
David

 

[Jamie Dundee]

If it’s a shoot through hull in an oil bath check that the oil hasn’t escaped.

 

[oldmanofthehills]

No real way to test the transducer but as its only a coil there is not much to go wrong short of it being disconnected due to break in the cable. Without knowing the desired impedance or capacitance it would be hard to determine much with a meter though I expect the resistance to be much less than infinite.

Mostly the echo sounder goes wrong. My old echo sounder gave results albeit unreliable with the wrong make of transducer when trying to work out which bit was duff.

 

[Porthandbuoy]

Can you hear it? Place a screwdriver against the transducer and press the handle to your ear. Doesn't work for me but does for my kids.

 

[harvey38]

Have you been out on the boat with the duff reading?

Had exactly the same problem on a boat this week that hadn't been out for a while, once off the dock, it came to life so suspect there was some debris/growth trapped under it.

 

[DavidGrieves]

If it’s a shoot through hull in an oil bath check that the oil hasn’t escaped.

No not a shoot through type, it’s in the hull with a skin fitting.

 

[syvictoria]

I'm sure that I tested ours at home using a toilet roll tube??!!! Or am I going quite mad??!!! Somehow this tricks the transducer into working, whilst holding it in mid air doesn't.

 

[Boathook]

Check the connections on the back of the display unit by removing and replacing. I had problems with my raymarin network the other week and unplugged and then replugged all the cables. System started to work.

 

[Pye_End]

Put radio 4 LW on the radio and listen for the ticking.

Would echo the connections checking comment.

 

[jamie N]

'Phone the manufacturer and ask them for the impedance that you should expect. Just the action of removing the connector and refitting it, might even clear a fault.

 

[MikeCC]

Usual problem with these is that water temperature thermistor fails. For whatever reason, the ST60 then doesn't recognise the transducer, hence dashes. The depth function is likely OK.

You'll find threads here and elsewhere on how to wire in a fixed resistor to make it work.

As jwilson says...

 

[jwilson]

Usual problem with these is that water temperature thermistor fails. For whatever reason, the ST60 then doesn't recognise the transducer, hence dashes. The depth function is likely OK.

You'll find threads here and elsewhere on how to wire in a fixed resistor to make it work.

I may be wrong but I thought that resistor across the Tridata fix was for a thermistor fault on the speed paddlewheel, not the depth transducer.

 

[MikeCC]

I may be wrong but I thought that resistor across the Tridata fix was for a thermistor fault on the speed paddlewheel, not the depth transducer.

Temperature is on the depth transducer.
Sorry, thinking of another transducer!

 

[ashtead]

Airmar transducers seem fairly unreliable. I guess you have newer unit with log paddle wheel plus depth in other half. They seem to pack up after a few years. I guess you might borrow another transducer to check if your marine electrician will lend you a spare just to see if info flows then. That’s what we did before getting a new one .