Tank Depth
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From: John Larkin on 4 Jul 2006 19:35 On Tue, 04 Jul 2006 15:50:22 -0700, "Paul Hovnanian P.E." <paul(a)hovnanian.com> wrote: >"James F. Mayer" wrote: >> >> I believe that a short time ago there was a discussion about this. but >> depending on the head of the tank one could use an MPX5000 series pressure >> sensor with a dip tube or am I too late? >> >> I have a number of 55 gal drums of water that I would like to know the >> depth of in my rain water gathering system so that I don't pump it dry and >> ruin a sprinkler pump. I am going to use one of them per drum to monitor >> the levels. I believe that the pressure of one foot of head is .43 PSI and >> that a drum is about 3 feet deep, giving a pressure of 1.29 PSI. Does this >> sound correct? > >That sounds about right. However ... > >This technique of measuring tank depth (quantity) may not work well over >a long period of time. In a washing machine, for example, the dip tube >only needs to maintain a reading for the duration of the fill cycle. I >suspect that slow leakage or air in the dip tube dissolving into the >water over longer periods (days, weeks) may reduce its accuracy. > On ships I've worked on, they used a "bubbler". That's a tube that enters a tank at the top and ends on the bottom. A needle valve admits compressed air to the top, and it slowly bubbles out of the bottom, and the back pressure indicates depth. It's especially used for petroleum products and other explosive liquids. John
From: Don Lancaster on 4 Jul 2006 19:54 James F. Mayer wrote: > I believe that a short time ago there was a discussion about this. but > depending on the head of the tank one could use an MPX5000 series pressure > sensor with a dip tube or am I too late? > > I have a number of 55 gal drums of water that I would like to know the > depth of in my rain water gathering system so that I don't pump it dry and > ruin a sprinkler pump. I am going to use one of them per drum to monitor > the levels. I believe that the pressure of one foot of head is .43 PSI and > that a drum is about 3 feet deep, giving a pressure of 1.29 PSI. Does this > sound correct? > > > Wouldn't a sensor to determine when the pump loses prime be simpler? -- Many thanks, Don Lancaster voice phone: (928)428-4073 Synergetics 3860 West First Street Box 809 Thatcher, AZ 85552 rss: http://www.tinaja.com/whtnu.xml email: don(a)tinaja.com Please visit my GURU's LAIR web site at http://www.tinaja.com
From: Jim Thompson on 4 Jul 2006 20:01 On Tue, 04 Jul 2006 15:50:22 -0700, "Paul Hovnanian P.E." <paul(a)hovnanian.com> wrote: >"James F. Mayer" wrote: >> >> I believe that a short time ago there was a discussion about this. but >> depending on the head of the tank one could use an MPX5000 series pressure >> sensor with a dip tube or am I too late? >> >> I have a number of 55 gal drums of water that I would like to know the >> depth of in my rain water gathering system so that I don't pump it dry and >> ruin a sprinkler pump. I am going to use one of them per drum to monitor >> the levels. I believe that the pressure of one foot of head is .43 PSI and >> that a drum is about 3 feet deep, giving a pressure of 1.29 PSI. Does this >> sound correct? > >That sounds about right. However ... > >This technique of measuring tank depth (quantity) may not work well over >a long period of time. In a washing machine, for example, the dip tube >only needs to maintain a reading for the duration of the fill cycle. I >suspect that slow leakage or air in the dip tube dissolving into the >water over longer periods (days, weeks) may reduce its accuracy. > That's the scenario I've been pondering. I'm trying to figure a way to measure (salt) aquarium level, for top off, that's reliable. I'm pondering a combination of washing-machine-style dip tube plus a (electro-mechanical) timer, to ensure that the tube clears before refill. Hopefully that would prevent false overfills due to air seepage from the dip tube. ...Jim Thompson -- | James E.Thompson, P.E. | mens | | Analog Innovations, Inc. | et | | Analog/Mixed-Signal ASIC's and Discrete Systems | manus | | Phoenix, Arizona Voice:(480)460-2350 | | | E-mail Address at Website Fax:(480)460-2142 | Brass Rat | | http://www.analog-innovations.com | 1962 | I love to cook with wine. Sometimes I even put it in the food.
From: James F. Mayer on 4 Jul 2006 20:22 "Jim Thompson" <To-Email-Use-The-Envelope-Icon(a)My-Web-Site.com> wrote in message news:r50ma2dsib6tk887j2p8r5522bq279j411(a)4ax.com... > On Tue, 04 Jul 2006 15:50:22 -0700, "Paul Hovnanian P.E." > <paul(a)hovnanian.com> wrote: > >>"James F. Mayer" wrote: >>> >>> I believe that a short time ago there was a discussion about this. but >>> depending on the head of the tank one could use an MPX5000 series >>> pressure >>> sensor with a dip tube or am I too late? >>> >>> I have a number of 55 gal drums of water that I would like to know >>> the >>> depth of in my rain water gathering system so that I don't pump it dry >>> and >>> ruin a sprinkler pump. I am going to use one of them per drum to >>> monitor >>> the levels. I believe that the pressure of one foot of head is .43 PSI >>> and >>> that a drum is about 3 feet deep, giving a pressure of 1.29 PSI. Does >>> this >>> sound correct? >> >>That sounds about right. However ... >> >>This technique of measuring tank depth (quantity) may not work well over >>a long period of time. In a washing machine, for example, the dip tube >>only needs to maintain a reading for the duration of the fill cycle. I >>suspect that slow leakage or air in the dip tube dissolving into the >>water over longer periods (days, weeks) may reduce its accuracy. >> > > That's the scenario I've been pondering. I'm trying to figure a way > to measure (salt) aquarium level, for top off, that's reliable. > > I'm pondering a combination of washing-machine-style dip tube plus a > (electro-mechanical) timer, to ensure that the tube clears before > refill. > > Hopefully that would prevent false overfills due to air seepage from > the dip tube. > Running some of the aerator air through the dip tube would solve that problem, I'd think.
From: James F. Mayer on 4 Jul 2006 20:27
"Don Lancaster" <don(a)tinaja.com> wrote in message news:4h0ddrF1p8n8iU2(a)individual.net... > James F. Mayer wrote: >> I believe that a short time ago there was a discussion about this. but >> depending on the head of the tank one could use an MPX5000 series >> pressure sensor with a dip tube or am I too late? >> >> I have a number of 55 gal drums of water that I would like to know >> the depth of in my rain water gathering system so that I don't pump it >> dry and ruin a sprinkler pump. I am going to use one of them per drum to >> monitor the levels. I believe that the pressure of one foot of head is >> .43 PSI and that a drum is about 3 feet deep, giving a pressure of 1.29 >> PSI. Does this sound correct? >> >> >> > Wouldn't a sensor to determine when the pump loses prime be simpler? > > Then I'd have to re-prime the pump. I would like to also be able to determine the amount remaining in the system if it isn't all pumped in the time allotted. |