Need a digital pressure sensor.

Discussion in 'General Electronics Chat' started by Razor Concepts, Jun 4, 2009.

  1. Razor Concepts

    Thread Starter Active Member

    Oct 7, 2008
    212
    1
    I am looking for a digital pressure sensor (for measuring alitude). I have seen Freescale's extensive line of pressure sensors but they have an analog out, which is not very accurate. Is there some kind of pressure sensor with digital communication like i2c or something? Thanks!
     
  2. hgmjr

    Moderator

    Jan 28, 2005
    9,030
    214
    What is the range in pressure that you need to measure?

    hgmjr
     
  3. Razor Concepts

    Thread Starter Active Member

    Oct 7, 2008
    212
    1
    I would like sea level (101.33 kPa or 760mm Hg) to about 1000 feet (97.63 kPa or 746.3mm Hg). Accuracy is important, doing some calculations with the analog-out sensors the accuracy is like +- 100ft which is too much.
     
  4. leftyretro

    Active Member

    Nov 25, 2008
    394
    2
    One thing to keep in mind, to measure altitude with a pressure sensor requires it to be of a absolute pressure type/model, not a gage or differential pressure type/model. I've seen several people order the wrong type for this application. Also if accuracy is important remember that you need to factor in the local barometric pressure variation as the standard/fixed altitude Vs absolute pressure formulas typically assume standard temperature/pressure conditions which is not the case in real life use. I used a aircraft VHF band radio to pick up broadcasts from local air fields as their station ID gives continuous local temp and barometric pressure.

    I found the analog output accuracy to be good enough for this kind of application as other physical variables will most likely swamp the results.

    Lefty
     
  5. bertus

    Administrator

    Apr 5, 2008
    15,647
    2,346
Loading...