<html><body><div style="color:#000; background-color:#fff; font-family:HelveticaNeue, Helvetica Neue, Helvetica, Arial, Lucida Grande, sans-serif;font-size:10pt"><div><span>Lasse,</span></div><div style="color: rgb(0, 0, 0); font-size: 13.333333969116211px; font-family: HelveticaNeue, 'Helvetica Neue', Helvetica, Arial, 'Lucida Grande', sans-serif; font-style: normal; background-color: transparent;"><span>I've seen a "splitter" or "junction box" you can buy for one of the echo sounders.</span></div><div style="color: rgb(0, 0, 0); font-size: 13.333333969116211px; font-family: HelveticaNeue, 'Helvetica Neue', Helvetica, Arial, 'Lucida Grande', sans-serif; font-style: normal; background-color: transparent;"><span>This enables input from 2 transducers to one screen. From memory the change</span></div><div style="color: rgb(0, 0, 0); font-size: 13.333333969116211px; font-family: HelveticaNeue, 'Helvetica Neue', Helvetica, Arial, 'Lucida Grande',
sans-serif; font-style: normal; background-color: transparent;"><span>over from one view to another wasn't that straight forward.</span></div><div style="color: rgb(0, 0, 0); font-size: 13.333333969116211px; font-family: HelveticaNeue, 'Helvetica Neue', Helvetica, Arial, 'Lucida Grande', sans-serif; font-style: normal; background-color: transparent;">I'm a bit vague about this, someone else may be able to give more information.</div><div style="color: rgb(0, 0, 0); font-size: 13.333333969116211px; font-family: HelveticaNeue, 'Helvetica Neue', Helvetica, Arial, 'Lucida Grande', sans-serif; font-style: normal; background-color: transparent;">All the best with the testing.</div><div style="color: rgb(0, 0, 0); font-size: 13.333333969116211px; font-family: HelveticaNeue, 'Helvetica Neue', Helvetica, Arial, 'Lucida Grande', sans-serif; font-style: normal; background-color: transparent;">Alan</div><div><br></div> <div style="font-family: HelveticaNeue,
'Helvetica Neue', Helvetica, Arial, 'Lucida Grande', sans-serif; font-size: 10pt;"> <div style="font-family: HelveticaNeue, 'Helvetica Neue', Helvetica, Arial, 'Lucida Grande', sans-serif; font-size: 12pt;"> <div dir="ltr"> <hr size="1"> <font size="2" face="Arial"> <b><span style="font-weight:bold;">From:</span></b> Lasse Schmidt via Personal_Submersibles <personal_submersibles@psubs.org><br> <b><span style="font-weight: bold;">To:</span></b> Personal Submersibles General Discussion <personal_submersibles@psubs.org> <br> <b><span style="font-weight: bold;">Sent:</span></b> Saturday, June 21, 2014 8:13 PM<br> <b><span style="font-weight: bold;">Subject:</span></b> Re: [PSUBS-MAILIST] Reversed echo sounder<br> </font> </div> <div class="y_msg_container"><br>wow, this is awesome thanks for the help. WeŽll have the chance to try this out next week. If it works, we will have both analogue and digital depth gauges.<br clear="none">IŽll make
sure to take some photos and upload them later.<br clear="none"><br clear="none">Lasse Schmidt<br clear="none">Upplevelsepresent.se<br clear="none">Skeppsbron 21, Tullhus 1<br clear="none">11130 Stockholm<br clear="none">070-28 32 660<br clear="none"><br clear="none">21 jun 2014 kl. 07:28 skrev Jens Laland via Personal_Submersibles <<a shape="rect" ymailto="mailto:personal_submersibles@psubs.org" href="mailto:personal_submersibles@psubs.org">personal_submersibles@psubs.org</a>>:<br clear="none"><br clear="none">> Lasse<br clear="none">> <br clear="none">> ** Is it possible to turn an echo sounder towards the surface to measure the<br clear="none">> ** distance to the surface?<br clear="none">> <br clear="none">> Because of the extreme (large) difference in characteristic acoustic<br clear="none">> impedance of seawater versus air, you will experience a sound power<br clear="none">> reflection coefficient of (typical)
0.99893 between seawater (@ +15°C) and<br clear="none">> air at sea level (@ +20°C).<br clear="none">> <br clear="none">> Simply stated, you will receive (echo) 99.893% of the sound send upwards<br clear="none">> from a submarine towards the surface.<br clear="none">> <br clear="none">> -------------------------------------------------------------------------<br clear="none">> <br clear="none">> SEAWATER (15°C)<br clear="none">> characteristic acoustic impedance : 1.5443675<br clear="none">> density : 1.025 SG<br clear="none">> longitudinal velocity of sound waves : 1506.7 m/sec<br clear="none">> wavelength @ 300 Hz : 5.02 m<br clear="none">> wavelength @ 948.683 Hz (center) : 1.59 m<br
clear="none">> wavelength @ 3000 Hz : 50.2 cm ( 19.773 inches )<br clear="none">> <br clear="none">> AIR, AT SEA LEVEL (+20°C)<br clear="none">> characteristic acoustic impedance : 0.0004132128<br clear="none">> density : 0.001204 SG<br clear="none">> longitudinal velocity of sound waves : 343.2 m/sec<br clear="none">> wavelength @ 300 Hz : 1.14 m<br clear="none">> wavelength @ 948.683 Hz (center) : 36.2 cm ( 14.243 inches )<br clear="none">> wavelength @ 3000 Hz : 11.4 cm ( 4.504 inches )<br clear="none">> <br
clear="none">> sound power reflection coefficient : 0.99893 ( 99.893 percent )<br clear="none">> <br clear="none">> -------------------------------------------------------------------------<br clear="none">> <br clear="none">> Best regards,<br clear="none">> Jens Laland<br clear="none">> <br clear="none">> <a shape="rect" href="http://traktoria.org/" target="_blank">http://traktoria.org</a><br clear="none">> -----------------------------<br clear="none">> My webpage works 100% with the Firefox Internet Browser, only<br clear="none">> <a shape="rect" href="http://www.mozilla.org/en-US/products/download.html?product=firefox" target="_blank">http://www.mozilla.org/en-US/products/download.html?product=firefox</a><br clear="none">> <br clear="none">> _______________________________________________<br clear="none">> Personal_Submersibles mailing list<br clear="none">> <a
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