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Ice thickness detector? mulling. — Parallax Forums

Ice thickness detector? mulling.

ArchiverArchiver Posts: 46,084
edited 2002-10-16 18:47 in General Discussion
While Its probably outside my capabilities at the moment, I was
wondering if its possible to make a small RF device to measure ice
thickness in a hockey arena. I got the idea while perusing web pages
and reading about RF "eyes" for robots.

Most modern arena's have a concrete slab which should be different
enough in its RF reflection properties to allow a sort of radar
distance measurement. Hold the senser against the ice surface and
shoot. The distance is the thickness of the ice (usually somewhere
between 3/4 and 1 1/2 inches).

Anyone ever see anything similar in their travels? Not that I think
I'm capable of making one by any means, but its something that would
be interesting to learn about.

Comments

  • ArchiverArchiver Posts: 46,084
    edited 2002-10-13 18:11
    You might consider ultrasonics instead of RF. (easier/cheaper). Your local
    home center already sells a device for next to nothing that would probably
    be easy to interface to a Stamp and that device is a "stud finder". The
    stud finder detects a change in density of the wall (ie: wall board) when
    swept across a stud and triggers an LED.

    Check the Parallax web site in the resources section and I believe there
    is an app note on ultrasonic range finders.

    The only potential problem I see is the accuracy that you are after. I'm
    not sure that the resoultion necessary to measure less than an inch will be
    possible to achieve with the Stamp/ultrasonic setup but it would be fun to
    try.

    Mike B.

    Original Message
    From: "ghidera2000" <ghidera2000@y...>
    To: <basicstamps@yahoogroups.com>
    Sent: Sunday, October 13, 2002 9:02 AM
    Subject: [noparse][[/noparse]basicstamps] Ice thickness detector? mulling.


    > While Its probably outside my capabilities at the moment, I was
    > wondering if its possible to make a small RF device to measure ice
    > thickness in a hockey arena. I got the idea while perusing web pages
    > and reading about RF "eyes" for robots.
    >
    > Most modern arena's have a concrete slab which should be different
    > enough in its RF reflection properties to allow a sort of radar
    > distance measurement. Hold the senser against the ice surface and
    > shoot. The distance is the thickness of the ice (usually somewhere
    > between 3/4 and 1 1/2 inches).
    >
    > Anyone ever see anything similar in their travels? Not that I think
    > I'm capable of making one by any means, but its something that would
    > be interesting to learn about.
    >
    >
    >
    > 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/
    >
    >
  • ArchiverArchiver Posts: 46,084
    edited 2002-10-14 08:01
    Two electronic approaches, both based on fixing a passive object to the
    concrete slab: 1) Infrared photo detector above the ice bouncing a beam
    off a polished metal mirror on the slab; and 2) a linear analog hall
    effect sensor (Allegra) above the ice, responding to a powerful magnet
    fastened to the slab. Both approaches could be "wet labbed" for
    accuracy in your kitchen with an ice cube.

    But for ultimate accuracy, plug in a soldering iron, apply the tip to
    the ice surface, and measure the protruding shaft after the tip hits the
    slab. Variations of this approach are well known to ice fisherman.

    Dennis

    Original Message
    From: ghidera2000 [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=N2hjTWeJggKmRh67QNqFfekKbPDrX-07HWHho-xE4yyK_595AjBQy6qh6R72EtiM-oV1KIa414qWq-U8]ghidera2000@y...[/url
    Sent: Sunday, October 13, 2002 9:03 AM
    To: basicstamps@yahoogroups.com
    Subject: [noparse][[/noparse]basicstamps] Ice thickness detector? mulling.


    While Its probably outside my capabilities at the moment, I was
    wondering if its possible to make a small RF device to measure ice
    thickness in a hockey arena. I got the idea while perusing web pages
    and reading about RF "eyes" for robots.

    Most modern arena's have a concrete slab which should be different
    enough in its RF reflection properties to allow a sort of radar
    distance measurement. Hold the senser against the ice surface and
    shoot. The distance is the thickness of the ice (usually somewhere
    between 3/4 and 1 1/2 inches).

    Anyone ever see anything similar in their travels? Not that I think
    I'm capable of making one by any means, but its something that would
    be interesting to learn about.



    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/
  • ArchiverArchiver Posts: 46,084
    edited 2002-10-14 08:39
    --- In basicstamps@y..., "Dennis P. O'Leary" <doleary@e...> wrote:
    > Two electronic approaches, both based on fixing a passive object
    to the
    > concrete slab: 1) Infrared photo detector above the ice bouncing
    a beam
    > off a polished metal mirror on the slab; and 2) a linear analog
    hall
    > effect sensor (Allegra) above the ice, responding to a powerful
    magnet
    > fastened to the slab. Both approaches could be "wet labbed" for
    > accuracy in your kitchen with an ice cube.

    Neither method would be practical really. Ice paint and
    scarring/oxidation of the ice would completely obsure a mirror.
    Hell, its hard enough just keeping the lines visible sometimes [noparse]:D[/noparse]
    Besides, hockey rinks are roughly 85x200 feet.

    > But for ultimate accuracy, plug in a soldering iron, apply the tip
    to
    > the ice surface, and measure the protruding shaft after the tip
    hits the
    > slab. Variations of this approach are well known to ice fisherman.

    Cordless drill and a ruler are what we use normally.

    > Dennis
    >
    >
    Original Message
    > From: ghidera2000 [noparse][[/noparse]mailto:ghidera2000@y...]
    > Sent: Sunday, October 13, 2002 9:03 AM
    > To: basicstamps@y...
    > Subject: [noparse][[/noparse]basicstamps] Ice thickness detector? mulling.
    >
    >
    > While Its probably outside my capabilities at the moment, I was
    > wondering if its possible to make a small RF device to measure ice
    > thickness in a hockey arena. I got the idea while perusing web
    pages
    > and reading about RF "eyes" for robots.
    >
    > Most modern arena's have a concrete slab which should be different
    > enough in its RF reflection properties to allow a sort of radar
    > distance measurement. Hold the senser against the ice surface and
    > shoot. The distance is the thickness of the ice (usually somewhere
    > between 3/4 and 1 1/2 inches).
    >
    > Anyone ever see anything similar in their travels? Not that I
    think
    > I'm capable of making one by any means, but its something that
    would
    > be interesting to learn about.
    >
    >
    >
    > 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/
  • ArchiverArchiver Posts: 46,084
    edited 2002-10-14 11:07
    Umm... I would think it has to be non-destructive and be capable of being
    used anywhere on the rink.

    Ultrasonic is still the best method so far, although it may be a challenge
    as well.

    Original Message


    > Two electronic approaches, both based on fixing a passive object to the
    > concrete slab: 1) Infrared photo detector above the ice bouncing a beam
    > off a polished metal mirror on the slab; and 2) a linear analog hall
    > effect sensor (Allegra) above the ice, responding to a powerful magnet
    > fastened to the slab. Both approaches could be "wet labbed" for
    > accuracy in your kitchen with an ice cube.
    >
    > But for ultimate accuracy, plug in a soldering iron, apply the tip to
    > the ice surface, and measure the protruding shaft after the tip hits the
    > slab. Variations of this approach are well known to ice fisherman.

    > While Its probably outside my capabilities at the moment, I was
    > wondering if its possible to make a small RF device to measure ice
    > thickness in a hockey arena. I got the idea while perusing web pages
    > and reading about RF "eyes" for robots.
    >
    > Most modern arena's have a concrete slab which should be different
    > enough in its RF reflection properties to allow a sort of radar
    > distance measurement. Hold the senser against the ice surface and
    > shoot. The distance is the thickness of the ice (usually somewhere
    > between 3/4 and 1 1/2 inches).
    >
    > Anyone ever see anything similar in their travels? Not that I think
    > I'm capable of making one by any means, but its something that would
    > be interesting to learn about.
  • ArchiverArchiver Posts: 46,084
    edited 2002-10-14 11:15
    The hardest part to using ultrasonic is the interface between the transducer
    and the ice.

    Duh -- how about a depth finder off a boat?

    Original Message

    > Umm... I would think it has to be non-destructive and be capable of being
    > used anywhere on the rink.
    >
    > Ultrasonic is still the best method so far, although it may be a challenge
    > as well.
    >
    >
    Original Message
    >
    >
    > > Two electronic approaches, both based on fixing a passive object to the
    > > concrete slab: 1) Infrared photo detector above the ice bouncing a beam
    > > off a polished metal mirror on the slab; and 2) a linear analog hall
    > > effect sensor (Allegra) above the ice, responding to a powerful magnet
    > > fastened to the slab. Both approaches could be "wet labbed" for
    > > accuracy in your kitchen with an ice cube.
    > >
    > > But for ultimate accuracy, plug in a soldering iron, apply the tip to
    > > the ice surface, and measure the protruding shaft after the tip hits the
    > > slab. Variations of this approach are well known to ice fisherman.
    >
    > > While Its probably outside my capabilities at the moment, I was
    > > wondering if its possible to make a small RF device to measure ice
    > > thickness in a hockey arena. I got the idea while perusing web pages
    > > and reading about RF "eyes" for robots.
    > >
    > > Most modern arena's have a concrete slab which should be different
    > > enough in its RF reflection properties to allow a sort of radar
    > > distance measurement. Hold the senser against the ice surface and
    > > shoot. The distance is the thickness of the ice (usually somewhere
    > > between 3/4 and 1 1/2 inches).
    > >
    > > Anyone ever see anything similar in their travels? Not that I think
    > > I'm capable of making one by any means, but its something that would
    > > be interesting to learn about.
  • ArchiverArchiver Posts: 46,084
    edited 2002-10-14 15:57
    The problem with ultrasonic's is the air to ice interface. The probe cannot
    have any air on top of the ice. You need to couple it with acoustical
    gel/liquid. In this case water would work. Then all you need to do is time
    the pulses, after determining the 'right' echo to listen to. You will get
    echoes from the transducer to ice interface, bubbles in the ice (if any), and
    the ice/cement interface.

    I don't know about measuring Ice, but I did work on a railroad rail
    application 10 years ago. We used mineral Oil in the transducer housing, and
    sprayed water on the rails for coupling. Using an 8051 type micro it had a
    hard time separating the different echo pulses. I assume it needed some DSP
    type of processing, and that was way beyond my Bit Bashing mentality. The
    project got canceled when the company went out of business.

    I know this isn't much help to find a solution, but hopefully it will help
    you avoid some pitfalls.

    Alan Bradford
    Plasma Technologies
  • ArchiverArchiver Posts: 46,084
    edited 2002-10-16 18:47
    I've been researching this more and I think maybe we've been thinking
    a bit too high tech.

    Think "Stud sensor". These somehow detect changes in density of the
    surface you're against (something about capacitance changes). Since
    most need some sort of zeroing before each use (some press a button
    when you're over "clear" wall, some use a thumbwheel) I would think
    that the capacitance changes could indicate thickness. This is
    somewhat backed up by what NASA is doing to detect ice layer
    thickness on the liquid fuel tank. Not sure if this would work for
    ice but, who knows [noparse]:D[/noparse] I'll do a little test here at work. Find a
    known thick area of ice to "zero" the sensor then run around and see
    what happens in thinner areas.
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