Best way or ways?

Closed Thread
Results 1 to 10 of 10

Hybrid View

  1. - 19th July 2013, 17:20 #1
    Ramius's Avatar
    Ramius
    Ramius is offline Contributor
    Join Date
    Mar 2011
    Location
    Los Angeles, California
    Posts
    322

    Question Best way or ways?

    Hi All!
    Soon I will receive my pressure sensor for measuring the pressure of water at different speeds. The plan is to place the sensor in a tub of water just under the surface and spin the sensor in a circle through the water at different speeds. The rotating arm will be about 8” long so that one revolution will be about 24” or 2’ of total travel. The motor that rotates the arm holding the sensor is connected to a switchable power supply. To determine speed you need to know how much time it takes to travel the 2’. There is a switch at the top which allows for a start/stop signal to trigger a timer in the PIC. I am not sure if I should use a counter and allow a start/stop of say 10 times to ensure an average in case there is a slight variance in pressure at each revolution and if I should allow the PIC program to continue to run and add a “Pause 100” and count the number of pause 100’s or simply activate some type of PIC timer? I welcome any and all ideas.

    Thanks, Ed
  2. - 20th July 2013, 07:17 #2
    Archangel's Avatar
    Archangel
    Archangel is offline SuperMod
    Join Date
    Aug 2006
    Location
    Look, behind you.
    Posts
    2,818

    Did you find this post helpful? Yes | No

    Default Re: Best way or ways?

    Hi Ed,
    Point to consider, when that rotating arm generates a vortex around it, what's going to happen to the pressure?
    These might be helpful . . .

    www.freescale.com/files/sensors/doc/app_note/AN1536.pdf

    www.v3instruments.com/trouble_shooting_guides/speedometer_pitot__ts.pdf
    Last edited by Archangel; - 20th July 2013 at 07:52.
    If you do not believe in MAGIC, Consider how currency has value simply by printing it, and is then traded for real assets.
    .
    Gold is the money of kings, silver is the money of gentlemen, barter is the money of peasants - but debt is the money of slaves
    .
    There simply is no "Happy Spam" If you do it you will disappear from this forum.
  3. - 20th July 2013, 18:04 #3
    rsocor01's Avatar
    rsocor01
    rsocor01 is offline Contributor
    Join Date
    Jan 2009
    Location
    Miami, Florida USA
    Posts
    699

    Did you find this post helpful? Yes | No

    Default Re: Best way or ways?

    Quote Originally Posted by Archangel View Post
    Point to consider, when that rotating arm generates a vortex around it, what's going to happen to the pressure?
    Very good point!!!

    I have seen several water pressure sensors for sale in mouser.com. I think that would be the way to go.

    Robert
    "No one is completely worthless. They can always serve as a bad example."

    Anonymous
  4. - 21st July 2013, 14:01 #4
    Ramius's Avatar
    Ramius
    Ramius is offline Contributor
    Join Date
    Mar 2011
    Location
    Los Angeles, California
    Posts
    322

    Did you find this post helpful? Yes | No

    Default Re: Best way or ways?

    Thanks Archangel and rsocor01!
    I would imagine that if the sensor is about 2-3" in front of the arm that there should not be any vortex at the point of measurement. The biggest question is how to measure travel time.

    Best, Ed
  5. - 21st July 2013, 20:13 #5
    Demon's Avatar
    Demon
    Demon is offline SuperMod
    Join Date
    Jan 2005
    Location
    Montreal, Quebec, Canada
    Posts
    3,159

    Did you find this post helpful? Yes | No

    Default Re: Best way or ways?

    Unless you use a large pool, the water will ever so slowly gradually rotate. I would think you get a true reading on 1st rotation and then it would decrease slowly with each rotation.

    Robert
  6. - 22nd July 2013, 00:45 #6
    Ramius's Avatar
    Ramius
    Ramius is offline Contributor
    Join Date
    Mar 2011
    Location
    Los Angeles, California
    Posts
    322

    Did you find this post helpful? Yes | No

    Default Re: Best way or ways?

    Thank Robert!
    I will certainly watch for this.

    Best, Ed
  7. - 22nd July 2013, 04:42 #7
    rsocor01's Avatar
    rsocor01
    rsocor01 is offline Contributor
    Join Date
    Jan 2009
    Location
    Miami, Florida USA
    Posts
    699

    Did you find this post helpful? Yes | No

    Default Re: Best way or ways?

    Quote Originally Posted by Ramius View Post
    The biggest question is how to measure travel time.

    Best, Ed
    What about a water flow sensor?
    http://futurlec.com/Flow_Sensor.shtml
    "No one is completely worthless. They can always serve as a bad example."

    Anonymous
  8. - 23rd July 2013, 22:18 #8
    Ramius's Avatar
    Ramius
    Ramius is offline Contributor
    Join Date
    Mar 2011
    Location
    Los Angeles, California
    Posts
    322

    Did you find this post helpful? Yes | No

    Default Re: Best way or ways?

    Thanks Rsocor01!
    If pressure does not work then this would be an excellent choice.

    Ed
« Previous Thread | Next Thread »

Similar Threads

  1. Ways to make code easily reviewable and extendable
    By Ted's in forum mel PIC BASIC Pro
    Replies: 14
    Last Post: - 23rd August 2008, 00:10
  2. Showing numbers in diffrent ways?
    By SuB-ZeRo in forum mel PIC BASIC Pro
    Replies: 1
    Last Post: - 29th July 2005, 15:57
  3. PIC problem, ways to do reset
    By lab310 in forum mel PIC BASIC Pro
    Replies: 1
    Last Post: - 26th May 2005, 14:31

Members who have read this thread : 0

You do not have permission to view the list of names.

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts

Forum Rules