Was:Pressure sensor - Air dissolving
Archiver
Posts: 46,084
Larry, All,
So, with the sensor mounted at the top of the tank, which is a
non-pressurized 7 ft deep open storage tank, you don't think the air in the
tube will slowly disolve into the water and cause long term calibration
issues? One aspect of the system is to prevent the tank from ever going
empty, so the tube will not have the air refreshed very often, if ever.
Jonathan
www.madlabs.info
Original Message
From: "Larry Gaminde" <lgaminde@t...>
To: <basicstamps@yahoogroups.com>
Sent: Friday, July 11, 2003 3:48 PM
Subject: Re: [noparse][[/noparse]basicstamps] Re: Pressure sensor for water tank - sensors
> I would say not really if the sensor is mounted at the top of the tank and
> you run a line to the bottom of the tank, using a pigtail will help. There
> may be water vapor in the air but isn't that a gas. Now if you mount the
> sensor in the bottom of the tank then you will or could have problems with
> calibration. The line could always be blown out with air, just put a tee
at
> the sensor with small valve hook air to the valve and open the valve until
> it bubbles then shut the valve off problem solved.
>
> Larry Gaminde
>
>
>
>
Original Message
> From: "Jonathan Peakall" <jpeakall@m...>
> To: <basicstamps@yahoogroups.com>
> Sent: July 11, 2003 2:10 PM
> Subject: Re: [noparse][[/noparse]basicstamps] Re: Pressure sensor for water tank - sensors
>
>
> > Larry,
> >
> > Someone pointed out that the air will dissolve into the water, giving
long
> > term calibration issues. What do you think?
> >
> > Jonathan
> >
> > www.madlabs.info
> >
> >
Original Message
> > From: "Larry Gaminde" <lgaminde@t...>
> > To: <basicstamps@yahoogroups.com>
> > Sent: Friday, July 11, 2003 1:08 PM
> > Subject: Re: [noparse][[/noparse]basicstamps] Re: Pressure sensor for water tank - sensors
> >
> >
> > > FYI
> > > 100 feet of water = 49.1154103 lbs of pressure
> > > 85 feet of water = 41.748098755 lbs of pressure
> > > 50 feet of water = 24.55770515 lbs of pressure
> > >
> > > you really don't need a pressure sensor rated for water, gas will
work!
> > > just keep the pressure sensor above water level and use a pigtail.
> > >
> > > Larry Gaminde
> > >
> > >
> > >
> > >
Original Message
> > > From: "Robert Ussery" <uavscience@f...>
> > > To: <basicstamps@yahoogroups.com>
> > > Sent: July 11, 2003 9:58 AM
> > > Subject: Re: [noparse][[/noparse]basicstamps] Re: Pressure sensor for water tank -
sensors
> > >
> > >
> > > > Sheesh, why not just use a cheap ~$20-40 pressure transducer good
for
> > > > water??? Several of the Motorola series are usable, and I have an
Ares
> > > > series one as sold in Digikey that says it can be used with
> > non-corrosive
> > > > liquids. I assume clean water fits the bill, especially if the
> sensor's
> > > > always wet.
> > > > Super easy to use, very accurate, and durable. Just have a port at
the
> > > > bottom of the tank and hook the transducer to it, and voila, you
have
> > the
> > > > water pressure. Some simple calculus, and you have depth.
> > > >
> > > >
> > > >
> > > > To UNSUBSCRIBE, just send mail to:
> > > > basicstamps-unsubscribe@yahoogroups.com
> > > > from the same email address that you subscribed. Text in the
Subject
> > and
> > > Body of the message will be ignored.
> > > >
> > > >
> > > > Your use of Yahoo! Groups is subject to
> > http://docs.yahoo.com/info/terms/
> > > >
> > > >
> > >
> > >
> > > To UNSUBSCRIBE, just send mail to:
> > > basicstamps-unsubscribe@yahoogroups.com
> > > from the same email address that you subscribed. Text in the Subject
> and
> > Body of the message will be ignored.
> > >
> > >
> > > Your use of Yahoo! Groups is subject to
> http://docs.yahoo.com/info/terms/
> > >
> > >
> > >
> > >
> > >
> >
> >
> > To UNSUBSCRIBE, just send mail to:
> > basicstamps-unsubscribe@yahoogroups.com
> > from the same email address that you subscribed. Text in the Subject
and
> Body of the message will be ignored.
> >
> >
> > Your use of Yahoo! Groups is subject to
http://docs.yahoo.com/info/terms/
> >
> >
>
>
> To UNSUBSCRIBE, just send mail to:
> basicstamps-unsubscribe@yahoogroups.com
> from the same email address that you subscribed. Text in the Subject and
Body of the message will be ignored.
>
>
> Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
>
>
>
>
>
So, with the sensor mounted at the top of the tank, which is a
non-pressurized 7 ft deep open storage tank, you don't think the air in the
tube will slowly disolve into the water and cause long term calibration
issues? One aspect of the system is to prevent the tank from ever going
empty, so the tube will not have the air refreshed very often, if ever.
Jonathan
www.madlabs.info
Original Message
From: "Larry Gaminde" <lgaminde@t...>
To: <basicstamps@yahoogroups.com>
Sent: Friday, July 11, 2003 3:48 PM
Subject: Re: [noparse][[/noparse]basicstamps] Re: Pressure sensor for water tank - sensors
> I would say not really if the sensor is mounted at the top of the tank and
> you run a line to the bottom of the tank, using a pigtail will help. There
> may be water vapor in the air but isn't that a gas. Now if you mount the
> sensor in the bottom of the tank then you will or could have problems with
> calibration. The line could always be blown out with air, just put a tee
at
> the sensor with small valve hook air to the valve and open the valve until
> it bubbles then shut the valve off problem solved.
>
> Larry Gaminde
>
>
>
>
Original Message
> From: "Jonathan Peakall" <jpeakall@m...>
> To: <basicstamps@yahoogroups.com>
> Sent: July 11, 2003 2:10 PM
> Subject: Re: [noparse][[/noparse]basicstamps] Re: Pressure sensor for water tank - sensors
>
>
> > Larry,
> >
> > Someone pointed out that the air will dissolve into the water, giving
long
> > term calibration issues. What do you think?
> >
> > Jonathan
> >
> > www.madlabs.info
> >
> >
Original Message
> > From: "Larry Gaminde" <lgaminde@t...>
> > To: <basicstamps@yahoogroups.com>
> > Sent: Friday, July 11, 2003 1:08 PM
> > Subject: Re: [noparse][[/noparse]basicstamps] Re: Pressure sensor for water tank - sensors
> >
> >
> > > FYI
> > > 100 feet of water = 49.1154103 lbs of pressure
> > > 85 feet of water = 41.748098755 lbs of pressure
> > > 50 feet of water = 24.55770515 lbs of pressure
> > >
> > > you really don't need a pressure sensor rated for water, gas will
work!
> > > just keep the pressure sensor above water level and use a pigtail.
> > >
> > > Larry Gaminde
> > >
> > >
> > >
> > >
Original Message
> > > From: "Robert Ussery" <uavscience@f...>
> > > To: <basicstamps@yahoogroups.com>
> > > Sent: July 11, 2003 9:58 AM
> > > Subject: Re: [noparse][[/noparse]basicstamps] Re: Pressure sensor for water tank -
sensors
> > >
> > >
> > > > Sheesh, why not just use a cheap ~$20-40 pressure transducer good
for
> > > > water??? Several of the Motorola series are usable, and I have an
Ares
> > > > series one as sold in Digikey that says it can be used with
> > non-corrosive
> > > > liquids. I assume clean water fits the bill, especially if the
> sensor's
> > > > always wet.
> > > > Super easy to use, very accurate, and durable. Just have a port at
the
> > > > bottom of the tank and hook the transducer to it, and voila, you
have
> > the
> > > > water pressure. Some simple calculus, and you have depth.
> > > >
> > > >
> > > >
> > > > To UNSUBSCRIBE, just send mail to:
> > > > basicstamps-unsubscribe@yahoogroups.com
> > > > from the same email address that you subscribed. Text in the
Subject
> > and
> > > Body of the message will be ignored.
> > > >
> > > >
> > > > Your use of Yahoo! Groups is subject to
> > http://docs.yahoo.com/info/terms/
> > > >
> > > >
> > >
> > >
> > > To UNSUBSCRIBE, just send mail to:
> > > basicstamps-unsubscribe@yahoogroups.com
> > > from the same email address that you subscribed. Text in the Subject
> and
> > Body of the message will be ignored.
> > >
> > >
> > > Your use of Yahoo! Groups is subject to
> http://docs.yahoo.com/info/terms/
> > >
> > >
> > >
> > >
> > >
> >
> >
> > To UNSUBSCRIBE, just send mail to:
> > basicstamps-unsubscribe@yahoogroups.com
> > from the same email address that you subscribed. Text in the Subject
and
> Body of the message will be ignored.
> >
> >
> > Your use of Yahoo! Groups is subject to
http://docs.yahoo.com/info/terms/
> >
> >
>
>
> To UNSUBSCRIBE, just send mail to:
> basicstamps-unsubscribe@yahoogroups.com
> from the same email address that you subscribed. Text in the Subject and
Body of the message will be ignored.
>
>
> Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
>
>
>
>
>
Comments
the tank so the water will never reach the sensor. I suppose the air will
saturate into the water some, but that's what the blow down tee corrects.
You could put a fitting in the tee and blow it down with a bicycle pump
every 6 months or whatever is needed you will be working with 14.252 lbs of
pressure at 7 ft. I also wonder just how much you can mix air with water
(static) and if it will really change things that much its still there just
mixed with water so the top 1/100 inch of water has more air in it.
Larry Gaminde
Original Message
From: "Jonathan Peakall" <jpeakall@m...>
To: <basicstamps@yahoogroups.com>
Sent: July 12, 2003 6:38 AM
Subject: [noparse][[/noparse]basicstamps] Was:Pressure sensor - Air dissolving
> Larry, All,
>
> So, with the sensor mounted at the top of the tank, which is a
> non-pressurized 7 ft deep open storage tank, you don't think the air in
the
> tube will slowly disolve into the water and cause long term calibration
> issues? One aspect of the system is to prevent the tank from ever going
> empty, so the tube will not have the air refreshed very often, if ever.
>
> Jonathan
>
> www.madlabs.info
>
>
Original Message
> From: "Larry Gaminde" <lgaminde@t...>
> To: <basicstamps@yahoogroups.com>
> Sent: Friday, July 11, 2003 3:48 PM
> Subject: Re: [noparse][[/noparse]basicstamps] Re: Pressure sensor for water tank - sensors
>
>
> > I would say not really if the sensor is mounted at the top of the tank
and
> > you run a line to the bottom of the tank, using a pigtail will help.
There
> > may be water vapor in the air but isn't that a gas. Now if you mount the
> > sensor in the bottom of the tank then you will or could have problems
with
> > calibration. The line could always be blown out with air, just put a tee
> at
> > the sensor with small valve hook air to the valve and open the valve
until
> > it bubbles then shut the valve off problem solved.
> >
> > Larry Gaminde
> >
> >
> >
> >
Original Message
> > From: "Jonathan Peakall" <jpeakall@m...>
> > To: <basicstamps@yahoogroups.com>
> > Sent: July 11, 2003 2:10 PM
> > Subject: Re: [noparse][[/noparse]basicstamps] Re: Pressure sensor for water tank - sensors
> >
> >
> > > Larry,
> > >
> > > Someone pointed out that the air will dissolve into the water, giving
> long
> > > term calibration issues. What do you think?
> > >
> > > Jonathan
> > >
> > > www.madlabs.info
> > >
> > >
Original Message
> > > From: "Larry Gaminde" <lgaminde@t...>
> > > To: <basicstamps@yahoogroups.com>
> > > Sent: Friday, July 11, 2003 1:08 PM
> > > Subject: Re: [noparse][[/noparse]basicstamps] Re: Pressure sensor for water tank -
sensors
> > >
> > >
> > > > FYI
> > > > 100 feet of water = 49.1154103 lbs of pressure
> > > > 85 feet of water = 41.748098755 lbs of pressure
> > > > 50 feet of water = 24.55770515 lbs of pressure
> > > >
> > > > you really don't need a pressure sensor rated for water, gas will
> work!
> > > > just keep the pressure sensor above water level and use a pigtail.
> > > >
> > > > Larry Gaminde
> > > >
> > > >
> > > >
> > > >
Original Message
> > > > From: "Robert Ussery" <uavscience@f...>
> > > > To: <basicstamps@yahoogroups.com>
> > > > Sent: July 11, 2003 9:58 AM
> > > > Subject: Re: [noparse][[/noparse]basicstamps] Re: Pressure sensor for water tank -
> sensors
> > > >
> > > >
> > > > > Sheesh, why not just use a cheap ~$20-40 pressure transducer good
> for
> > > > > water??? Several of the Motorola series are usable, and I have an
> Ares
> > > > > series one as sold in Digikey that says it can be used with
> > > non-corrosive
> > > > > liquids. I assume clean water fits the bill, especially if the
> > sensor's
> > > > > always wet.
> > > > > Super easy to use, very accurate, and durable. Just have a port at
> the
> > > > > bottom of the tank and hook the transducer to it, and voila, you
> have
> > > the
> > > > > water pressure. Some simple calculus, and you have depth.
> > > > >
> > > > >
> > > > >
> > > > > To UNSUBSCRIBE, just send mail to:
> > > > > basicstamps-unsubscribe@yahoogroups.com
> > > > > from the same email address that you subscribed. Text in the
> Subject
> > > and
> > > > Body of the message will be ignored.
> > > > >
> > > > >
> > > > > Your use of Yahoo! Groups is subject to
> > > http://docs.yahoo.com/info/terms/
> > > > >
> > > > >
> > > >
> > > >
> > > > To UNSUBSCRIBE, just send mail to:
> > > > basicstamps-unsubscribe@yahoogroups.com
> > > > from the same email address that you subscribed. Text in the
Subject
> > and
> > > Body of the message will be ignored.
> > > >
> > > >
> > > > Your use of Yahoo! Groups is subject to
> > http://docs.yahoo.com/info/terms/
> > > >
> > > >
> > > >
> > > >
> > > >
> > >
> > >
> > > To UNSUBSCRIBE, just send mail to:
> > > basicstamps-unsubscribe@yahoogroups.com
> > > from the same email address that you subscribed. Text in the Subject
> and
> > Body of the message will be ignored.
> > >
> > >
> > > Your use of Yahoo! Groups is subject to
> http://docs.yahoo.com/info/terms/
> > >
> > >
> >
> >
> > To UNSUBSCRIBE, just send mail to:
> > basicstamps-unsubscribe@yahoogroups.com
> > from the same email address that you subscribed. Text in the Subject
and
> Body of the message will be ignored.
> >
> >
> > Your use of Yahoo! Groups is subject to
http://docs.yahoo.com/info/terms/
> >
> >
> >
> >
> >
>
>
> To UNSUBSCRIBE, just send mail to:
> basicstamps-unsubscribe@yahoogroups.com
> from the same email address that you subscribed. Text in the Subject and
Body of the message will be ignored.
>
>
> Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
>
>
the tube. If the temperature in the tube increases, at constant
pressure, its volume also increases. The effect is that bubbles come
out the bottom of the tube. When the temperature drops again, water
rises up in the tube, so that the level indicated is no longer the
full pressure. Subsequently, as temperature fluctuates during the
day, the apparent level will fluctuate also. Every time the weather
hits a new high temperature record, more bubbles are lost at the
bottom.
"Bubbler" systems continuously supply dry air or nitrogen from a tank
at a slow rate so that bubbles are always coming out the bottom of
the tube, and so that the pressure indicated correctly is the
hydrostatic pressure bottom of the tube.
Differential transducers meant for mounting in the bottom of the tank
have a moisture barrier stainless steel diaphragm ~1 mil thick
transmitting. Good ones are expensive, because proper temperature
compensation of bridge transducers is a big part of the accuracy.
-- Tracy
>Larry, All,
>
>So, with the sensor mounted at the top of the tank, which is a
>non-pressurized 7 ft deep open storage tank, you don't think the air in the
>tube will slowly disolve into the water and cause long term calibration
>issues? One aspect of the system is to prevent the tank from ever going
>empty, so the tube will not have the air refreshed very often, if ever.
>
>Jonathan
>
>www.madlabs.info
>
>
Original Message
>From: "Larry Gaminde" <lgaminde@t...>
>To: <basicstamps@yahoogroups.com>
>Sent: Friday, July 11, 2003 3:48 PM
>Subject: Re: [noparse][[/noparse]basicstamps] Re: Pressure sensor for water tank - sensors
>
>
>> I would say not really if the sensor is mounted at the top of the tank and
>> you run a line to the bottom of the tank, using a pigtail will help. There
>> may be water vapor in the air but isn't that a gas. Now if you mount the
>> sensor in the bottom of the tank then you will or could have problems with
>> calibration. The line could always be blown out with air, just put a tee
>at
>> the sensor with small valve hook air to the valve and open the valve until
>> it bubbles then shut the valve off problem solved.
>>
>> Larry Gaminde
>>
>>
>>
>>
Original Message
>> From: "Jonathan Peakall" <jpeakall@m...>
>> To: <basicstamps@yahoogroups.com>
>> Sent: July 11, 2003 2:10 PM
>> Subject: Re: [noparse][[/noparse]basicstamps] Re: Pressure sensor for water tank - sensors
>>
>>
>> > Larry,
>> >
>> > Someone pointed out that the air will dissolve into the water, giving
>long
>> > term calibration issues. What do you think?
>> >
>> > Jonathan
>> >
>> > www.madlabs.info
>> >
>> >
Original Message
>> > From: "Larry Gaminde" <lgaminde@t...>
>> > To: <basicstamps@yahoogroups.com>
>> > Sent: Friday, July 11, 2003 1:08 PM
>> > Subject: Re: [noparse][[/noparse]basicstamps] Re: Pressure sensor for water tank - sensors
>> >
>> >
>> > > FYI
>> > > 100 feet of water = 49.1154103 lbs of pressure
>> > > 85 feet of water = 41.748098755 lbs of pressure
>> > > 50 feet of water = 24.55770515 lbs of pressure
>> > >
>> > > you really don't need a pressure sensor rated for water, gas will
>work!
>> > > just keep the pressure sensor above water level and use a pigtail.
>> > >
>> > > Larry Gaminde
>> > >
>> > >
>> > >
>> > >
Original Message
>> > > From: "Robert Ussery" <uavscience@f...>
>> > > To: <basicstamps@yahoogroups.com>
>> > > Sent: July 11, 2003 9:58 AM
>> > > Subject: Re: [noparse][[/noparse]basicstamps] Re: Pressure sensor for water tank -
>sensors
>> > >
>> > >
>> > > > Sheesh, why not just use a cheap ~$20-40 pressure transducer good
>for
>> > > > water??? Several of the Motorola series are usable, and I have an
>Ares
>> > > > series one as sold in Digikey that says it can be used with
>> > non-corrosive
>> > > > liquids. I assume clean water fits the bill, especially if the
>> sensor's
>> > > > always wet.
>> > > > Super easy to use, very accurate, and durable. Just have a port at
>the
>> > > > bottom of the tank and hook the transducer to it, and voila, you
>have
>> > the
>> > > > water pressure. Some simple calculus, and you have depth.
>> > > >
>> > > >
>> > > >
>> > > > To UNSUBSCRIBE, just send mail to:
>> > > > basicstamps-unsubscribe@yahoogroups.com
>> > > > from the same email address that you subscribed. Text in the
>Subject
>> > and
>> > > Body of the message will be ignored.
>> > > >
>> > > >
>> > > > Your use of Yahoo! Groups is subject to
>> > http://docs.yahoo.com/info/terms/
>> > > >
>> > > >
>> > >
>> > >
>> > > To UNSUBSCRIBE, just send mail to:
>> > > basicstamps-unsubscribe@yahoogroups.com
>> > > from the same email address that you subscribed. Text in the Subject
>> and
>> > Body of the message will be ignored.
>> > >
>> > >
>> > > Your use of Yahoo! Groups is subject to
>> http://docs.yahoo.com/info/terms/
>> > >
>> > >
>> > >
>> > >
>> > >
>> >
>> >
>> > To UNSUBSCRIBE, just send mail to:
>> > basicstamps-unsubscribe@yahoogroups.com
>> > from the same email address that you subscribed. Text in the Subject
>and
>> Body of the message will be ignored.
>> >
>> >
>> > Your use of Yahoo! Groups is subject to
>http://docs.yahoo.com/info/terms/
>> >
>> >
>>
>>
>> To UNSUBSCRIBE, just send mail to:
>> basicstamps-unsubscribe@yahoogroups.com
>> from the same email address that you subscribed. Text in the Subject and
>Body of the message will be ignored.
>>
>>
>> Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
>>
>>
>>
>>
>>
>
>
>To UNSUBSCRIBE, just send mail to:
> basicstamps-unsubscribe@yahoogroups.com
>from the same email address that you subscribed. Text in the
>Subject and Body of the message will be ignored.
>
>
>Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/