Underwater Ping?

RichardF

Do you think Ping transducers would work underwater (fresh water, low conductance)? I am back working with my U/W ROV and I would like to add fathometer capability (cheaply).

Phil Pilgrim (PhiPi)

Not a chance. Even if they survived the immersion, their mechanical impedance is designed for coupling to air, not to water. Moreover, they lack the power output required for use as a depth sounder.

My advice would be to shop CraigsList, eBay, and garage sales for a depth sounder that you can hack.

-Phil

RichardF

Got it, thanks.

macrobeak

RichardF,
I have been interested for underwater ultrasonic ranging as well. I have done some research but I have been unable to uncover any cheap and user-friendly devices similar to Ping. Please keep your post alive and report back on any success.

Beau Schwabe

Consider this: ... you don't necessarily need to use ultrasonics above human hearing to detect object distance.

Here is a project I helped a 5th grade student prepare to prove the speed of sound... using a speaker and a microphone.

http://forums.parallax.com/showthread.php?122467-Proving-the-Speed-of-Sound-5th-grade-science-fair-project&p=906892&viewfull=1#post906892

I mention this because something like a piezo might be a better fit for an underwater application than an ultrasonic transducer would. (As a kid I used piezo's to listen to radio underwater in our home pool)

W9GFO

Lots of transducers on eBay, here's one for $39;

http://www.ebay.com/itm/NEW-P32-200kHz-Depth-Speed-Transducer-/180907479225?pt=Boat_Parts_Accessories_Gear&hash=item2a1eed10b9&vxp=mtr#ht_500wt_1413

Mark_T

W9GFO wrote: »

Lots of transducers on eBay, here's one for $39;

http://www.ebay.com/itm/NEW-P32-200kHz-Depth-Speed-Transducer-/180907479225?pt=Boat_Parts_Accessories_Gear&hash=item2a1eed10b9&vxp=mtr#ht_500wt_1413

Might be a bit over-spec'd at 300W rms and >=400 foot range

kwinn

Mark_T wrote: »

Might be a bit over-spec'd at 300W rms and >=400 foot range

True, but unless it comes with an amplifier you don't have to run it at 300W.

Phil Pilgrim (PhiPi)

Do a Google search for nmea depth transducer. You will get links to active transducers that output serial data in NMEA format, similar to that of GPS.

-Phil