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</o:shapelayout></xml><![endif]--></head><body lang=EN-US link="#0563C1" vlink="#954F72"><div class=WordSection1><p class=MsoNormal><font size=2 color="#1f497d" face=Calibri><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D'>Hydrostatic level sensors are fairly common in the industrial controls market. They consist of a single-ended pressure sensor that is suspended in a fluid. As the fluid level increases above the sensor, the pressure increases. A 4-20mA or 0-10VDC signal coming from the sensor can then be calibrated in feet or meters of level above the sensor.<o:p></o:p></span></font></p><p class=MsoNormal><font size=2 color="#1f497d" face=Calibri><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D'><o:p> </o:p></span></font></p><p class=MsoNormal><font size=2 color="#1f497d" face=Calibri><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D'>I’ve used the following Endress+Hauser sensor to measure water level in a condenser water sump in a chilled water plant:<o:p></o:p></span></font></p><p class=MsoNormal><font size=2 color="#1f497d" face=Calibri><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D'><o:p> </o:p></span></font></p><p class=MsoNormal><font size=2 color="#1f497d" face=Calibri><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D'><a href="http://www.us.endress.com/en/Tailor-made-field-instrumentation/pressure/Hydrostatic-level-Waterpilot-FMX21">http://www.us.endress.com/en/Tailor-made-field-instrumentation/pressure/Hydrostatic-level-Waterpilot-FMX21</a><o:p></o:p></span></font></p><p class=MsoNormal><font size=2 color="#1f497d" face=Calibri><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D'><o:p> </o:p></span></font></p><p class=MsoNormal><font size=2 color="#1f497d" face=Calibri><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D'>I forget what the price was—probably between $1,000 and $5,000. It might be outside your price range, but the concept of using pressure to measure level is sound.<o:p></o:p></span></font></p><p class=MsoNormal><font size=2 color="#1f497d" face=Calibri><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D'><o:p> </o:p></span></font></p><p class=MsoNormal><font size=2 color="#1f497d" face=Calibri><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D'>Bob…<o:p></o:p></span></font></p><p class=MsoNormal><font size=2 color="#1f497d" face=Calibri><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D'><o:p> </o:p></span></font></p><div style='border:none;border-left:solid blue 1.5pt;padding:0in 0in 0in 4.0pt'><div><div style='border:none;border-top:solid #E1E1E1 1.0pt;padding:3.0pt 0in 0in 0in'><p class=MsoNormal><b><font size=2 face=Calibri><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;font-weight:bold'>From:</span></font></b><font size=2 face=Calibri><span style='font-size:11.0pt;font-family:"Calibri",sans-serif'> aprssig [mailto:aprssig-bounces@tapr.org] <b><span style='font-weight:bold'>On Behalf Of </span></b>Robert Bruninga via aprssig<br><b><span style='font-weight:bold'>Sent:</span></b> Sunday, October 04, 2015 10:03 PM<br><b><span style='font-weight:bold'>To:</span></b> TAPR APRS Mailing List <aprssig@tapr.org><br><b><span style='font-weight:bold'>Subject:</span></b> [aprssig] water level gauge for APRS<o:p></o:p></span></font></p></div></div><p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:12.0pt'><o:p> </o:p></span></font></p><div><div><div><div><p class=MsoNormal style='margin-bottom:12.0pt'><font size=3 face="Times New Roman"><span style='font-size:12.0pt'>TO make a flood gage, it would seem that a simply pressure sensor like we use for atomosphere for balloon payloads would work.<o:p></o:p></span></font></p></div><p class=MsoNormal style='margin-bottom:12.0pt'><font size=3 face="Times New Roman"><span style='font-size:12.0pt'>Just put it inside a pipe with a cap on the top and open on the bottom. Then the pressure will vary with the height of the water. Connect this to the analog input of an APRS tracker and you have a flood gage. Calibate it with some testing and done...<o:p></o:p></span></font></p></div><p class=MsoNormal style='margin-bottom:12.0pt'><font size=3 face="Times New Roman"><span style='font-size:12.0pt'>ANyone done this?<o:p></o:p></span></font></p></div><p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:12.0pt'>Bob<o:p></o:p></span></font></p></div></div></div></body></html>