Pressure sensor
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Posts: 46,084
Greetings,
I'm looking for a water pressure sensor I can attach to a BS2. It
should hopefully be small and reasonably priced. Need a voltage output
proportional (not necessarily linear) to the water pressure. The idea is
to use this in a small Autonomous Underwater Vehicle to recognize zero
buoyancy. When the pressure is not changing the vehicle is maintaining
depth, when pressure is increasing it is diving, etc. Any suggestions
appreciated.
Regards, Theron Wierenga
Muskegon, Michigan
I'm looking for a water pressure sensor I can attach to a BS2. It
should hopefully be small and reasonably priced. Need a voltage output
proportional (not necessarily linear) to the water pressure. The idea is
to use this in a small Autonomous Underwater Vehicle to recognize zero
buoyancy. When the pressure is not changing the vehicle is maintaining
depth, when pressure is increasing it is diving, etc. Any suggestions
appreciated.
Regards, Theron Wierenga
Muskegon, Michigan
Comments
Fritz
Original Message
From: "Theron Wierenga" <twiereng@m...>
To: <basicstamps@yahoogroups.com>
Sent: Wednesday, February 21, 2001 10:13 PM
Subject: [noparse][[/noparse]basicstamps] Pressure sensor
> Greetings,
>
> I'm looking for a water pressure sensor I can attach to a BS2. It
> should hopefully be small and reasonably priced. Need a voltage output
> proportional (not necessarily linear) to the water pressure. The idea is
> to use this in a small Autonomous Underwater Vehicle to recognize zero
> buoyancy. When the pressure is not changing the vehicle is maintaining
> depth, when pressure is increasing it is diving, etc. Any suggestions
> appreciated.
>
> Regards, Theron Wierenga
> Muskegon, Michigan
>
>
>
> Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
>
>
>
This will probably not be used in water over 50 feet deep, if we could
get an 8 bit reading over this kind of range it would suffice.
Theron
Fritz Braun wrote:
>
> What sort of pressure ranges , precision and accuracy are you looking for?
>
> Fritz
>
Original Message
> From: "Theron Wierenga" <twiereng@m...>
> To: <basicstamps@yahoogroups.com>
> Sent: Wednesday, February 21, 2001 10:13 PM
> Subject: [noparse][[/noparse]basicstamps] Pressure sensor
>
> > Greetings,
> >
> > I'm looking for a water pressure sensor I can attach to a BS2. It
> > should hopefully be small and reasonably priced. Need a voltage output
> > proportional (not necessarily linear) to the water pressure. The idea is
> > to use this in a small Autonomous Underwater Vehicle to recognize zero
> > buoyancy. When the pressure is not changing the vehicle is maintaining
> > depth, when pressure is increasing it is diving, etc. Any suggestions
> > appreciated.
> >
> > Regards, Theron Wierenga
> > Muskegon, Michigan
> >
> >
> >
> > Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
> >
> >
> >
>
>
>
> Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
I am working on a similar project, an autonomous submarine with a
design dive depth of 125 feet. Over these kinds of pressure ranges
and accuracies, we are finding an automative oil pressure transducer
to be a very workable sensor solution, especially considering the $20
price range compared with $150 and up for industrial units.
Remember that water pressure is about 1 atmosphere / 15 feet of
depth, so to dive to 50 feet you would need a sensor capable of
measuring up to (50 / 15) = 3.5 (margin for error) + 1 (for the
actual atmosphere above that) = 4.5 atmospheres of pressure. This is
equivalent to about 70 pounds per square inch.
I am not sure if you will see an accurate, timely enough signal from
differentiating such a sensor to finely control your bouyancy, that
seems like quite a task to me, especially considering many bouyancy
systems are difficult to control and do not respond well to the kind
of low-hysteresis-induced cycling that this may produce, but I'm sure
with enough tinkering you can get something workable.
Good luck, and if you have more questions I'd be happy to do what I
can,
Douglas McClean
jxm156@p... or IDiggles@a...
--- In basicstamps@y..., Theron Wierenga <twiereng@m...> wrote:
> Greetings,
>
> I'm looking for a water pressure sensor I can attach to a
BS2. It
> should hopefully be small and reasonably priced. Need a voltage
output
> proportional (not necessarily linear) to the water pressure. The
idea is
> to use this in a small Autonomous Underwater Vehicle to recognize
zero
> buoyancy. When the pressure is not changing the vehicle is
maintaining
> depth, when pressure is increasing it is diving, etc. Any
suggestions
> appreciated.
>
> Regards, Theron Wierenga
> Muskegon, Michigan
> Remember that water pressure is about 1 atmosphere / 15 feet of
> depth, so to dive to 50 feet you would need a sensor capable of
one atm is 33 feet
Thanks for the reply, we'll give this a try. Do you know what type of
output we will get from this? Another question is have you found a source for
an "inexpensive" solenoid operated valve for something like a 1/4 inch line?
Regards, Theron
IDiggles@a... wrote:
> Theron,
> I am working on a similar project, an autonomous submarine with a
> design dive depth of 125 feet. Over these kinds of pressure ranges
> and accuracies, we are finding an automative oil pressure transducer
> to be a very workable sensor solution, especially considering the $20
> price range compared with $150 and up for industrial units.
>
> Remember that water pressure is about 1 atmosphere / 15 feet of
> depth, so to dive to 50 feet you would need a sensor capable of
> measuring up to (50 / 15) = 3.5 (margin for error) + 1 (for the
> actual atmosphere above that) = 4.5 atmospheres of pressure. This is
> equivalent to about 70 pounds per square inch.
>
> I am not sure if you will see an accurate, timely enough signal from
> differentiating such a sensor to finely control your bouyancy, that
> seems like quite a task to me, especially considering many bouyancy
> systems are difficult to control and do not respond well to the kind
> of low-hysteresis-induced cycling that this may produce, but I'm sure
> with enough tinkering you can get something workable.
>
> Good luck, and if you have more questions I'd be happy to do what I
> can,
> Douglas McClean
> jxm156@p... or IDiggles@a...
>
> --- In basicstamps@y..., Theron Wierenga <twiereng@m...> wrote:
> > Greetings,
> >
> > I'm looking for a water pressure sensor I can attach to a
> BS2. It
> > should hopefully be small and reasonably priced. Need a voltage
> output
> > proportional (not necessarily linear) to the water pressure. The
> idea is
> > to use this in a small Autonomous Underwater Vehicle to recognize
> zero
> > buoyancy. When the pressure is not changing the vehicle is
> maintaining
> > depth, when pressure is increasing it is diving, etc. Any
> suggestions
> > appreciated.
> >
> > Regards, Theron Wierenga
> > Muskegon, Michigan
>
>
>
> Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
ACJacques
34 feet.
--
"They that can give up essential liberty to obtain a
little temporary safety deserve neither liberty nor
safety." - Benjamin Franklin
>
> On Thu, 22 Feb 2001, IDiggles@a... wrote:
>
> > Remember that water pressure is about 1 atmosphere / 15 feet of
> > depth, so to dive to 50 feet you would need a sensor capable of
>
> one atm is 33 feet
>
>
>
> Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
>
>
Depending on what pressure range you need, you may want to look at the
PX240 series from www.omega.com. Prices start at $149. You can pick
from several different pressure ranges. BTW, request Omega's Reference
Set -- 6 hardback volumes packed with cool sensors, instrumentation, and
technical info -- all for free. Phone is 800-222-2665.
On Wed, 21 Feb 2001 22:58:27 -0500 Theron Wierenga
<twiereng@m...> writes:
> Fritz,
>
> This will probably not be used in water over 50 feet deep,
> if we could
> get an 8 bit reading over this kind of range it would suffice.
>
> Theron
>
> Fritz Braun wrote:
> >
> > What sort of pressure ranges , precision and accuracy are you
> looking for?
> >
> > Fritz
> >
Original Message
> > From: "Theron Wierenga" <twiereng@m...>
> > To: <basicstamps@yahoogroups.com>
> > Sent: Wednesday, February 21, 2001 10:13 PM
> > Subject: [noparse][[/noparse]basicstamps] Pressure sensor
> >
> > > Greetings,
> > >
> > > I'm looking for a water pressure sensor I can attach to a BS2.
> It
> > > should hopefully be small and reasonably priced. Need a voltage
> output
> > > proportional (not necessarily linear) to the water pressure. The
> idea is
> > > to use this in a small Autonomous Underwater Vehicle to
> recognize zero
> > > buoyancy. When the pressure is not changing the vehicle is
> maintaining
> > > depth, when pressure is increasing it is diving, etc. Any
> suggestions
> > > appreciated.
> > >
> > > Regards, Theron Wierenga
> > > Muskegon, Michigan
> > >
> > >
> > >
> > > Your use of Yahoo! Groups is subject to
> http://docs.yahoo.com/info/terms/
> > >
> > >
> > >
> >
> >
> >
> > Your use of Yahoo! Groups is subject to
> http://docs.yahoo.com/info/terms/
>
>
>
> Your use of Yahoo! Groups is subject to
> http://docs.yahoo.com/info/terms/
>
>
and the FIRST 34 feet in fresh water.
The second is only about ____ feet? less than 20
it's been so long since those SCUBA lessons.
Pressure at depth will be somewhat logrymithic, not linear.
--- In basicstamps@y..., arlen.fletcher@a... wrote:
> Unless you're in fresh water - where one atmosphere is
> 34 feet.
>
> --
> "They that can give up essential liberty to obtain a
> little temporary safety deserve neither liberty nor
> safety." - Benjamin Franklin
> >
> > On Thu, 22 Feb 2001, IDiggles@a... wrote:
> >
> > > Remember that water pressure is about 1 atmosphere / 15 feet of
> > > depth, so to dive to 50 feet you would need a sensor capable of
> >
> > one atm is 33 feet
> >
> >
> >
> > Your use of Yahoo! Groups is subject to
http://docs.yahoo.com/info/terms/
> >
> >
Each atm in fresh water happening at multiples of 33 feet.
With a surface gas mixture becoming poisinous(?) at 330 feet, 10 atms.
Mike
davemucha@j... wrote:
> OK, The FIRST 33 feet in Salt water is one Atsm,
> and the FIRST 34 feet in fresh water.
>
> The second is only about ____ feet? less than 20
> it's been so long since those SCUBA lessons.
>
> Pressure at depth will be somewhat logrymithic, not linear.
>
> --- In basicstamps@y..., arlen.fletcher@a... wrote:
> > Unless you're in fresh water - where one atmosphere is
> > 34 feet.
> >
> > --
> > "They that can give up essential liberty to obtain a
> > little temporary safety deserve neither liberty nor
> > safety." - Benjamin Franklin
> > >
> > > On Thu, 22 Feb 2001, IDiggles@a... wrote:
> > >
> > > > Remember that water pressure is about 1 atmosphere / 15 feet of
> > > > depth, so to dive to 50 feet you would need a sensor capable of
> > >
> > > one atm is 33 feet
> > >
> > >
> > >
> > > Your use of Yahoo! Groups is subject to
> http://docs.yahoo.com/info/terms/
> > >
> > >
>
>
>
> Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
> I remember the pressure being linear and not log...whatever.
> Each atm in fresh water happening at multiples of 33 feet.
> With a surface gas mixture becoming poisinous(?) at 330 feet, 10
atms.
>
> Mike
>
> davemucha@j... wrote:
>
> > OK, The FIRST 33 feet in Salt water is one Atsm,
> > and the FIRST 34 feet in fresh water.
> >
> > The second is only about ____ feet? less than 20
> > it's been so long since those SCUBA lessons.
> >
> > Pressure at depth will be somewhat logrymithic, not linear.
> >
> > --- In basicstamps@y..., arlen.fletcher@a... wrote:
> > > Unless you're in fresh water - where one atmosphere is
> > > 34 feet.
> > >
> > > --
> > > "They that can give up essential liberty to obtain a
> > > little temporary safety deserve neither liberty nor
> > > safety." - Benjamin Franklin
> > > >
> > > > On Thu, 22 Feb 2001, IDiggles@a... wrote:
> > > >
> > > > > Remember that water pressure is about 1 atmosphere / 15
feet of
> > > > > depth, so to dive to 50 feet you would need a sensor
capable of
> > > >
> > > > one atm is 33 feet
> > > >
> > > >
> > > >
> > > > Your use of Yahoo! Groups is subject to
> > http://docs.yahoo.com/info/terms/
> > > >
> > > >
> >
> >
> >
> > Your use of Yahoo! Groups is subject to
http://docs.yahoo.com/info/terms/
was compised of a little plastic tube and air was log.
As the depth compressed th air in the tube, it read similar to a
thermometer. you could really see the line between water and air.
as the air compredded, the scale was not linear. it was logrymitic.
like I said, so may years ago. anybody know Lloyd Bridges e-mail
address?
--- In basicstamps@y..., Mike Eggleston <mikee@m...> wrote:
> I remember the pressure being linear and not log...whatever.
> Each atm in fresh water happening at multiples of 33 feet.
> With a surface gas mixture becoming poisinous(?) at 330 feet, 10
atms.
>
> Mike
>
> davemucha@j... wrote:
>
> > OK, The FIRST 33 feet in Salt water is one Atsm,
> > and the FIRST 34 feet in fresh water.
> >
> > The second is only about ____ feet? less than 20
> > it's been so long since those SCUBA lessons.
> >
> > Pressure at depth will be somewhat logrymithic, not linear.
> >
> > --- In basicstamps@y..., arlen.fletcher@a... wrote:
> > > Unless you're in fresh water - where one atmosphere is
> > > 34 feet.
> > >
> > > --
> > > "They that can give up essential liberty to obtain a
> > > little temporary safety deserve neither liberty nor
> > > safety." - Benjamin Franklin
> > > >
> > > > On Thu, 22 Feb 2001, IDiggles@a... wrote:
> > > >
> > > > > Remember that water pressure is about 1 atmosphere / 15
feet of
> > > > > depth, so to dive to 50 feet you would need a sensor
capable of
> > > >
> > > > one atm is 33 feet
> > > >
> > > >
> > > >
> > > > Your use of Yahoo! Groups is subject to
> > http://docs.yahoo.com/info/terms/
> > > >
> > > >
> >
> >
> >
> > Your use of Yahoo! Groups is subject to
http://docs.yahoo.com/info/terms/
> was compised of a little plastic tube and air was log.
>
> As the depth compressed th air in the tube, it read similar to a
> thermometer. you could really see the line between water and air.
> as the air compredded, the scale was not linear. it was logrymitic.
That was a consequence of the instrument.
Pressure increases by one atmosphere (14.7psi, 1 bar) for every 33
feet (34 in fresh water) linearly. 66 feet = 2atm, 99 feet=3atm, etc.
33 feet of sea water weighs the same as a column of air from the
sea to the beginning of space.
Your guage (you are showing your age) works according to Boyles
law which says that if you double the pressure, you halve the
volume (of a gas). So if the bubble was 1 inch long at the surface (1
atm) at 33 feet there is a total of 2atm (water plus air) so the
bubble is 0.5" long. At 66 feet there are 2atm of water plus one of
air so the bubble is one third the original length. At 99 feet the
bubble is a quarter, 132 feet one fifth, etc.
The pressure increases linearly but the volume of your bubble is log
(well 1/x actually but it has that log look about it).
> like I said, so may years ago. anybody know Lloyd Bridges e-mail
> address?
You _are_ showing your age. :-)
Steve.
======================================================
Steve Baldwin Electronic Product Design
TLA Microsystems Ltd Microcontroller Specialists
PO Box 15-680, New Lynn http://www.tla.co.nz
Auckland, New Zealand ph +64 9 820-2221
email: steveb@t... fax +64 9 820-1929
======================================================
> > anybody know Lloyd Bridges e-mail address?
> You _are_ showing your age. :-)
> Steve.
I was thinking about flow pressure and not static pressure.
In a duct, the pressure from a Pitot tube is a log function.
Pressure of water depth, as you stated is linear. It is also a simple
device to calibrate. Since the salinity and temperature don't change
much over time, you can just drop a measuring tape in with your
sensor to check your software calibration.
Does Diver Dan have a URL?
Dave
>
>
> ======================================================
> Steve Baldwin Electronic Product Design
> TLA Microsystems Ltd Microcontroller Specialists
> PO Box 15-680, New Lynn http://www.tla.co.nz
> Auckland, New Zealand ph +64 9 820-2221
> email: steveb@t... fax +64 9 820-1929
> ======================================================
Differentional pressure transmitter MPX5100DP
- Sensor output 0.5 - 4.5 Volt in the pressure range from 0 - 100kPa ( 0 -
±10 meter water)
- Power supply 5 Volt
- I = 8 mA
- accuracy unknown
Prize : Euro 36.28
Order no. 18.38.90-24 page 568 of the catalog 2001, see www.conrad.com
(check for water resistance)
Best regards
Piet Deen
Oorspronkelijk bericht
Van: Theron Wierenga <twiereng@m...>
Aan: <basicstamps@yahoogroups.com>
Verzonden: donderdag 22 februari 2001 4:13
Onderwerp: [noparse][[/noparse]basicstamps] Pressure sensor
> Greetings,
>
> I'm looking for a water pressure sensor I can attach to a BS2. It
> should hopefully be small and reasonably priced. Need a voltage output
> proportional (not necessarily linear) to the water pressure. The idea is
> to use this in a small Autonomous Underwater Vehicle to recognize zero
> buoyancy. When the pressure is not changing the vehicle is maintaining
> depth, when pressure is increasing it is diving, etc. Any suggestions
> appreciated.
>
> Regards, Theron Wierenga
> Muskegon, Michigan
>
>
>
> Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
>
>
>
pressure sensor. I am interested in 10hpa to 1100hpa
range. Been looking for 2 weeks now and I am not able
to locate an appropriate one for my project. I came
across ones that are over $500. I need something
within $100. Any suggestions?
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bunch of different models in various pressure ranges and configurations
(differential, absolute, etc). Digikey carries several series of inexpensive
pressure transducers, mostly <$100. Look around! ;o)
Robert
kambms@y... writes:
> I am looking for a small size and light weight
> pressure sensor. I am interested in 10hpa to 1100hpa
> range. Been looking for 2 weeks now and I am not able
> to locate an appropriate one for my project. I came
> across ones that are over $500. I need something
> within $100. Any suggestions?
>
I am not sure of the units (hpa) but at a junk yard you could get a vehicle
Manifold Absolute Pressure Sensor that will measure 0 to 15 psi
absoulute.....
[noparse][[/noparse]Non-text portions of this message have been removed]
All Sensors Corp.
6296 San Ignacio, Ste. E
San Jose, CA 95119
Voice 408-225-4314, Fax 408-225-2079
and/or their site.
Original Message
From: "Ali" <kambms@y...>
To: <basicstamps@yahoogroups.com>
Sent: Friday, February 14, 2003 20:41
Subject: [noparse][[/noparse]basicstamps] Pressure Sensor
>
> I am looking for a small size and light weight
> pressure sensor. I am interested in 10hpa to 1100hpa
> range. Been looking for 2 weeks now and I am not able
> to locate an appropriate one for my project. I came
> across ones that are over $500. I need something
> within $100. Any suggestions?
>
>
>
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