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Prox sensor MORE DETAIL — Parallax Forums

Prox sensor MORE DETAIL

ArchiverArchiver Posts: 46,084
edited 2001-07-10 04:21 in General Discussion
All getting a bit complex....
The ONLY info we need is a go/no-go level at a certain point to indiacted
whern the level in the silo falls below a certain point. The type of product
varies in size and density regularly.


Original Message
From: <gbrecke@y...>
To: <basicstamps@yahoogroups.com>
Sent: Monday, July 09, 2001 4:42 AM
Subject: [noparse][[/noparse]basicstamps] Re: RE:Prox sensor


> I'm not sure the goal has been well established yet.
>
> Is this silo used to store this material exclusively? If so,
> could you use sonar to determine the presence of this material
> and a the volume as well?
>
> George B.
>
>
> --- In basicstamps@y..., s premena <premzee@j...> wrote:
> > It would help if you could give the minimum amount of weight
> > you need to detect. And what sort of granular size.
> >
> > For reliable detection I'd suggest some sort of vibrating
> > assembly [noparse][[/noparse]could be piezo] - the frequency and energy it
> > takes to drive it would vary as it was surrounded with
> > material. This assumes that the sensor enclosure material is
> > flexible. The vibration would also tend to clean dust off.
> > Is the stuff flammable? [noparse][[/noparse]static electric charge could be
> > an issue].
> >
> > For just pressure you could have a capacitive bridge with
> > grounded outer plates which would squeeze toward an inner
> > plate. Here the issue would be what would stay uniform over
> > time squeezing and un squeezing. Perhaps silicone rubber
> > between aluminum plates would work.
> >
> > Interlink Electronics has resistive material which changes
> > with pressure on it.
> >
> > There are membrane elastomers used in keyboards which change
> > resistance with pressure.
> >
> > Without knowing how much pressure - min and max - you are
> > trying to work with it's all up in the guessing region.
> >
> >
> > >>
> > Date: Fri, 6 Jul 2001 08:28:42 +0930
> > From: "Tim Stockman, STOCKMAN ELECTRONICS" <stocky@c...>
> > ...
> > I am looking for a circuit that will be suitable to detect the
> presence
> > of a granular fertilizer in a storage silo. Just need a go/no-go
> type
> > output eg whether the sensor is covered or not.
> > <<
> >
> > ________________________________________________________________
> > GET INTERNET ACCESS FROM JUNO!
> > Juno offers FREE or PREMIUM Internet access for less!
> > Join Juno today! For your FREE software, visit:
> > http://dl.www.juno.com/get/tagj.
>
>
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Body of the message will be ignored.
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Comments

  • ArchiverArchiver Posts: 46,084
    edited 2001-07-09 13:38
    I still say a spring loaded flapper / magnet in the silo coupled with a reed
    switch or hall-effect sensor on the outside is the most simple solution.

    Original Message

    > The ONLY info we need is a go/no-go level at a certain point to indiacted
    > whern the level in the silo falls below a certain point. The type of
    product
    > varies in size and density regularly.
  • ArchiverArchiver Posts: 46,084
    edited 2001-07-09 13:44
    Would a simple through-beam photo-sensor work?

    in brief:
    LED emitter | silo | LED Detector

    Daniel

    Original Message
    From: Tim Stockman, STOCKMAN ELECTRONICS [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=IyiEPq6oc3q7uJd7S4K6zODgF5H6xYs0qb0gDMFN8pNTiXlRK65uTDZSdbHaaenKwEo1tTJIs5Hgop_EnMw]stocky@c...[/url
    Sent: Sunday, 08 July 2001 20:26
    To: basicstamps@yahoogroups.com
    Subject: Re: [noparse][[/noparse]basicstamps] Re: RE:Prox sensor MORE DETAIL


    All getting a bit complex....
    The ONLY info we need is a go/no-go level at a certain point to indiacted
    whern the level in the silo falls below a certain point. The type of product
    varies in size and density regularly.


    Original Message
    From: <gbrecke@y...>
    To: <basicstamps@yahoogroups.com>
    Sent: Monday, July 09, 2001 4:42 AM
    Subject: [noparse][[/noparse]basicstamps] Re: RE:Prox sensor


    > I'm not sure the goal has been well established yet.
    >
    > Is this silo used to store this material exclusively? If so,
    > could you use sonar to determine the presence of this material
    > and a the volume as well?
    >
    > George B.
    >
    >
    > --- In basicstamps@y..., s premena <premzee@j...> wrote:
    > > It would help if you could give the minimum amount of weight
    > > you need to detect. And what sort of granular size.
    > >
    > > For reliable detection I'd suggest some sort of vibrating
    > > assembly [noparse][[/noparse]could be piezo] - the frequency and energy it
    > > takes to drive it would vary as it was surrounded with
    > > material. This assumes that the sensor enclosure material is
    > > flexible. The vibration would also tend to clean dust off.
    > > Is the stuff flammable? [noparse][[/noparse]static electric charge could be
    > > an issue].
    > >
    > > For just pressure you could have a capacitive bridge with
    > > grounded outer plates which would squeeze toward an inner
    > > plate. Here the issue would be what would stay uniform over
    > > time squeezing and un squeezing. Perhaps silicone rubber
    > > between aluminum plates would work.
    > >
    > > Interlink Electronics has resistive material which changes
    > > with pressure on it.
    > >
    > > There are membrane elastomers used in keyboards which change
    > > resistance with pressure.
    > >
    > > Without knowing how much pressure - min and max - you are
    > > trying to work with it's all up in the guessing region.
    > >
    > >
    > > >>
    > > Date: Fri, 6 Jul 2001 08:28:42 +0930
    > > From: "Tim Stockman, STOCKMAN ELECTRONICS" <stocky@c...>
    > > ...
    > > I am looking for a circuit that will be suitable to detect the
    > presence
    > > of a granular fertilizer in a storage silo. Just need a go/no-go
    > type
    > > output eg whether the sensor is covered or not.
    > > <<
    > >
    > > ________________________________________________________________
    > > GET INTERNET ACCESS FROM JUNO!
    > > Juno offers FREE or PREMIUM Internet access for less!
    > > Join Juno today! For your FREE software, visit:
    > > http://dl.www.juno.com/get/tagj.
    >
    >
    > 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/
    >
    >


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  • ArchiverArchiver Posts: 46,084
    edited 2001-07-09 14:13
    I have used Omron proximity sensors for sensing when their was enough ice
    for large ice making machines. The device has an IR transmitter/ receiver
    pair mounted side by side. When the medium is close enough (ice in my case),
    the reflection of the IR transmitter is picked up by the IR receiver,
    closing a dry contact or a transistor depending on the model.

    Brad Watts / AMT
    E-mail BradWatts@a...
    Web www.amt.nb.ca

    Original Message
    From: D. Daniel McGlothin [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=oaa2joAsS5ilqNHG5lruXh1Jn5Sd8luHsCWShaTl2EolVAQzAlaOfmDBFjf6LsQQc2jEh3QYZs7NQQ]ddm_stamps@y...[/url
    Sent: Monday, July 09, 2001 9:44 AM
    To: basicstamps@yahoogroups.com
    Subject: RE: [noparse][[/noparse]basicstamps] Re: RE:Prox sensor MORE DETAIL

    Would a simple through-beam photo-sensor work?

    in brief:
    LED emitter | silo | LED Detector

    Daniel

    Original Message
    From: Tim Stockman, STOCKMAN ELECTRONICS [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=XxUBtoUw-gxNrANO28aA2zw7nGPq61vvoxBlUFFzkfsZdM9ZyXdDnMR-ESQ2AeaF8roiN0ohNzXaDknGEQ]stocky@c...[/url
    Sent: Sunday, 08 July 2001 20:26
    To: basicstamps@yahoogroups.com
    Subject: Re: [noparse][[/noparse]basicstamps] Re: RE:Prox sensor MORE DETAIL


    All getting a bit complex....
    The ONLY info we need is a go/no-go level at a certain point to indiacted
    whern the level in the silo falls below a certain point. The type of product
    varies in size and density regularly.


    Original Message
    From: <gbrecke@y...>
    To: <basicstamps@yahoogroups.com>
    Sent: Monday, July 09, 2001 4:42 AM
    Subject: [noparse][[/noparse]basicstamps] Re: RE:Prox sensor


    > I'm not sure the goal has been well established yet.
    >
    > Is this silo used to store this material exclusively? If so,
    > could you use sonar to determine the presence of this material
    > and a the volume as well?
    >
    > George B.
    >
    >
    > --- In basicstamps@y..., s premena <premzee@j...> wrote:
    > > It would help if you could give the minimum amount of weight
    > > you need to detect. And what sort of granular size.
    > >
    > > For reliable detection I'd suggest some sort of vibrating
    > > assembly [noparse][[/noparse]could be piezo] - the frequency and energy it
    > > takes to drive it would vary as it was surrounded with
    > > material. This assumes that the sensor enclosure material is
    > > flexible. The vibration would also tend to clean dust off.
    > > Is the stuff flammable? [noparse][[/noparse]static electric charge could be
    > > an issue].
    > >
    > > For just pressure you could have a capacitive bridge with
    > > grounded outer plates which would squeeze toward an inner
    > > plate. Here the issue would be what would stay uniform over
    > > time squeezing and un squeezing. Perhaps silicone rubber
    > > between aluminum plates would work.
    > >
    > > Interlink Electronics has resistive material which changes
    > > with pressure on it.
    > >
    > > There are membrane elastomers used in keyboards which change
    > > resistance with pressure.
    > >
    > > Without knowing how much pressure - min and max - you are
    > > trying to work with it's all up in the guessing region.
    > >
    > >
    > > >>
    > > Date: Fri, 6 Jul 2001 08:28:42 +0930
    > > From: "Tim Stockman, STOCKMAN ELECTRONICS" <stocky@c...>
    > > ...
    > > I am looking for a circuit that will be suitable to detect the
    > presence
    > > of a granular fertilizer in a storage silo. Just need a go/no-go
    > type
    > > output eg whether the sensor is covered or not.
    > > <<
    > >
    > > ________________________________________________________________
    > > GET INTERNET ACCESS FROM JUNO!
    > > Juno offers FREE or PREMIUM Internet access for less!
    > > Join Juno today! For your FREE software, visit:
    > > http://dl.www.juno.com/get/tagj.
    >
    >
    > 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:
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    Body of the message will be ignored.


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  • ArchiverArchiver Posts: 46,084
    edited 2001-07-09 21:19
    This environment appears to be a nasty one. The materials probably
    contain dust that could coat lenses or windows making a light device
    less reliable unless some type of self cleaning device is
    incorporated.... which would up the cost and lower the reliability.

    In addition, some fertilizers "clump" if the moisture content is not
    controlled. At this point, this is unknown and has to be taken into
    account. Can you engineer an (inexpensive) mechanical device that
    would shake off this potentially corrosive stuff and assure it was
    not present when the silo level is lowered?

    If a sonar device were mounted high in the silo, you could sense any
    level you wished and gather even more data than you require today.
    But more importantly, your sensors would be up out of these elements
    where they can more readily cope with such an environment.

    George B.









    --- In basicstamps@y..., "Brad Watts" <bradwatts@b...> wrote:
    > I have used Omron proximity sensors for sensing when their was
    enough ice
    > for large ice making machines. The device has an IR transmitter/
    receiver
    > pair mounted side by side. When the medium is close enough (ice in
    my case),
    > the reflection of the IR transmitter is picked up by the IR
    receiver,
    > closing a dry contact or a transistor depending on the model.
    >
    > Brad Watts / AMT
    > E-mail BradWatts@a...
    > Web www.amt.nb.ca
    >
    >
    Original Message
    > From: D. Daniel McGlothin [noparse][[/noparse]mailto:ddm_stamps@y...]
    > Sent: Monday, July 09, 2001 9:44 AM
    > To: basicstamps@y...
    > Subject: RE: [noparse][[/noparse]basicstamps] Re: RE:Prox sensor MORE DETAIL
    >
    > Would a simple through-beam photo-sensor work?
    >
    > in brief:
    > LED emitter | silo | LED Detector
    >
    > Daniel
    >
    >
    Original Message
    > From: Tim Stockman, STOCKMAN ELECTRONICS [noparse][[/noparse]mailto:stocky@c...]
    > Sent: Sunday, 08 July 2001 20:26
    > To: basicstamps@y...
    > Subject: Re: [noparse][[/noparse]basicstamps] Re: RE:Prox sensor MORE DETAIL
    >
    >
    > All getting a bit complex....
    > The ONLY info we need is a go/no-go level at a certain point to
    indiacted
    > whern the level in the silo falls below a certain point. The type
    of product
    > varies in size and density regularly.
    >
    >
    >
    Original Message
    > From: <gbrecke@y...>
    > To: <basicstamps@y...>
    > Sent: Monday, July 09, 2001 4:42 AM
    > Subject: [noparse][[/noparse]basicstamps] Re: RE:Prox sensor
    >
    >
    > > I'm not sure the goal has been well established yet.
    > >
    > > Is this silo used to store this material exclusively? If so,
    > > could you use sonar to determine the presence of this material
    > > and a the volume as well?
    > >
    > > George B.
    > >
    > >
    > > --- In basicstamps@y..., s premena <premzee@j...> wrote:
    > > > It would help if you could give the minimum amount of weight
    > > > you need to detect. And what sort of granular size.
    > > >
    > > > For reliable detection I'd suggest some sort of vibrating
    > > > assembly [noparse][[/noparse]could be piezo] - the frequency and energy it
    > > > takes to drive it would vary as it was surrounded with
    > > > material. This assumes that the sensor enclosure material is
    > > > flexible. The vibration would also tend to clean dust off.
    > > > Is the stuff flammable? [noparse][[/noparse]static electric charge could be
    > > > an issue].
    > > >
    > > > For just pressure you could have a capacitive bridge with
    > > > grounded outer plates which would squeeze toward an inner
    > > > plate. Here the issue would be what would stay uniform over
    > > > time squeezing and un squeezing. Perhaps silicone rubber
    > > > between aluminum plates would work.
    > > >
    > > > Interlink Electronics has resistive material which changes
    > > > with pressure on it.
    > > >
    > > > There are membrane elastomers used in keyboards which change
    > > > resistance with pressure.
    > > >
    > > > Without knowing how much pressure - min and max - you are
    > > > trying to work with it's all up in the guessing region.
    > > >
    > > >
    > > > >>
    > > > Date: Fri, 6 Jul 2001 08:28:42 +0930
    > > > From: "Tim Stockman, STOCKMAN ELECTRONICS" <stocky@c...>
    > > > ...
    > > > I am looking for a circuit that will be suitable to detect the
    > > presence
    > > > of a granular fertilizer in a storage silo. Just need a go/no-
    go
    > > type
    > > > output eg whether the sensor is covered or not.
    > > > <<
    > > >
    > > > ________________________________________________________________
    > > > GET INTERNET ACCESS FROM JUNO!
    > > > Juno offers FREE or PREMIUM Internet access for less!
    > > > Join Juno today! For your FREE software, visit:
    > > > http://dl.www.juno.com/get/tagj.
    > >
    > >
    > > To UNSUBSCRIBE, just send mail to:
    > > basicstamps-unsubscribe@y...
    > > 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@y...
    > 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
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    >
    >
    >
    > _________________________________________________________
    >
    > Do You Yahoo!?
    >
    > Get your free @yahoo.com address at http://mail.yahoo.com
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    >
    >
    >
    > To UNSUBSCRIBE, just send mail to:
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    > Body of the message will be ignored.
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  • ArchiverArchiver Posts: 46,084
    edited 2001-07-09 22:10
    Unless they make a sonar unit with a plastic diaphragm, this probably would
    not work. I would think the fertilizer dust / moisture would tend to corrode
    the metal diaphragm found in most ultrasonic transducers.

    What about a piece of pipe with a hole in it every so often. Pump air into
    the pipe at a known rate of flow and monitor the pressure. The higher the
    level of material, the higher the pressure. Of course you would have to
    figure out how to keep the material out of the hole.

    Original Message


    > This environment appears to be a nasty one. The materials probably
    > contain dust that could coat lenses or windows making a light device
    > less reliable unless some type of self cleaning device is
    > incorporated.... which would up the cost and lower the reliability.
    >
    > In addition, some fertilizers "clump" if the moisture content is not
    > controlled. At this point, this is unknown and has to be taken into
    > account. Can you engineer an (inexpensive) mechanical device that
    > would shake off this potentially corrosive stuff and assure it was
    > not present when the silo level is lowered?
    >
    > If a sonar device were mounted high in the silo, you could sense any
    > level you wished and gather even more data than you require today.
    > But more importantly, your sensors would be up out of these elements
    > where they can more readily cope with such an environment.
  • ArchiverArchiver Posts: 46,084
    edited 2001-07-10 03:53
    They mount some form of ultrasonic transducer on the back of trucks
    to guage distance. I would think that was a fairly lousy environment
    for a piece of metal... so maybe it uses a stainless diaphragm or
    at least a powder coated one??





    --- In basicstamps@y..., Rodent <daweasel@s...> wrote:
    > Unless they make a sonar unit with a plastic diaphragm, this
    probably would
    > not work. I would think the fertilizer dust / moisture would tend
    to corrode
    > the metal diaphragm found in most ultrasonic transducers.
    >
    > What about a piece of pipe with a hole in it every so often. Pump
    air into
    > the pipe at a known rate of flow and monitor the pressure. The
    higher the
    > level of material, the higher the pressure. Of course you would
    have to
    > figure out how to keep the material out of the hole.
    >
    >
    Original Message
    >
    >
    > > This environment appears to be a nasty one. The materials probably
    > > contain dust that could coat lenses or windows making a light
    device
    > > less reliable unless some type of self cleaning device is
    > > incorporated.... which would up the cost and lower the
    reliability.
    > >
    > > In addition, some fertilizers "clump" if the moisture content is
    not
    > > controlled. At this point, this is unknown and has to be taken
    into
    > > account. Can you engineer an (inexpensive) mechanical device that
    > > would shake off this potentially corrosive stuff and assure it was
    > > not present when the silo level is lowered?
    > >
    > > If a sonar device were mounted high in the silo, you could sense
    any
    > > level you wished and gather even more data than you require today.
    > > But more importantly, your sensors would be up out of these
    elements
    > > where they can more readily cope with such an environment.
  • ArchiverArchiver Posts: 46,084
    edited 2001-07-10 04:21
    Fertilizer is really nasty, probably more so than road salt. Not only is it
    corrosive, but it attracts moisture. In a silo alot of dust would be
    created, which would find its way onto any exposed metal. Stainless would
    probably hold up well, assuming you can find a transducer with a stainless
    diaphragm.


    Original Message

    > They mount some form of ultrasonic transducer on the back of trucks
    > to guage distance. I would think that was a fairly lousy environment
    > for a piece of metal... so maybe it uses a stainless diaphragm or
    > at least a powder coated one??

    > > Unless they make a sonar unit with a plastic diaphragm, this
    > probably would
    > > not work. I would think the fertilizer dust / moisture would tend
    > to corrode
    > > the metal diaphragm found in most ultrasonic transducers.
    > >
    > > What about a piece of pipe with a hole in it every so often. Pump
    > air into
    > > the pipe at a known rate of flow and monitor the pressure. The
    > higher the
    > > level of material, the higher the pressure. Of course you would
    > have to
    > > figure out how to keep the material out of the hole.
    > >
    > >
    Original Message
    > >
    > >
    > > > This environment appears to be a nasty one. The materials probably
    > > > contain dust that could coat lenses or windows making a light
    > device
    > > > less reliable unless some type of self cleaning device is
    > > > incorporated.... which would up the cost and lower the
    > reliability.
    > > >
    > > > In addition, some fertilizers "clump" if the moisture content is
    > not
    > > > controlled. At this point, this is unknown and has to be taken
    > into
    > > > account. Can you engineer an (inexpensive) mechanical device that
    > > > would shake off this potentially corrosive stuff and assure it was
    > > > not present when the silo level is lowered?
    > > >
    > > > If a sonar device were mounted high in the silo, you could sense
    > any
    > > > level you wished and gather even more data than you require today.
    > > > But more importantly, your sensors would be up out of these
    > elements
    > > > where they can more readily cope with such an environment.
    >
    >
    > 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/
    >
    >
    >
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