1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

A Programatically measure air pressure within a piston

  1. Feb 17, 2017 #1
    I am a software engineer. I am working on an experimental project to attempt
    to measure in real time the variation in air pressure (relative to the ambient
    pressure of the room) in a piston style apparatus. In this model, I am expectant that there will be a measureable change in the internal pressure as the surrounding air is compressed. I am no clearly physician, so looking
    to purchase a sensor with a supported SDK. That way I can calibrate the readings
    within software and produce a real time graph of the variations resulting
    from compressing the space within the cyclinder. I am seeking recommendations
    as to the type of sensor readings I would need to measure and an idea of the type
    of physical sensor I should be looking to purchase. I am hoping the sensor will
    be reasonable in price as this is just an experiment, which might have an actual
    real world application. Thanks in advance for any and all suggestions.
  2. jcsd
  3. Feb 17, 2017 #2


    User Avatar
    Science Advisor
    Gold Member

    To select a pressure sensor we need information about pressures , temperatures , response rates and means of attachment .

    It may be possible to determine what happens in the cylinder theoretically - have you considered this ?
  4. Feb 17, 2017 #3
    Thanks for response. This is more of a practical experiment than a theoretical one. I am currently investigation various solutions, but am uncertain as to whether the types of gear I am looking at are suitable for application. I read that the atmospheric air pressure is at sea level is defined as 1013 mbar, 101.3 (kPa), 1.013 bar, which is about 14.7 Pounds per square inch (PSI). I need to determine the likely positive and negative delta I could reasonably expect in a cylinder as the air is both compressed to maximum and released as a minimum. I realise this hasn't addressed your questions for which I apologise, but like I said I am working with unknowns at this point. I am wondering if something as simple as this type of sensor would suffice (http://uk.rs-online.com/web/p/pressure-sensors/3987045/).
  5. Feb 17, 2017 #4
    Clearly the example provided is not digital, but you get the idea. Ideally I am looking for a digital sensor that can handle the types of pressure deltas expected and support those readings through an exposed SDK.
  6. Feb 18, 2017 #5
    You haven't mentioned the range you wish to measure nor the accuracy you want.

    The sensor you linked to is a switch, it simply tells you if the pressure is above or below a certain amount (closed/open). From your earlier post I assumed you want to do a pressure reading.
  7. Feb 18, 2017 #6


    User Avatar

    Staff: Mentor

    Can you provide more detail about what you are trying to measure, how you are trying to measure it and why? It sounds like you are trying to reinvent the wheel here, but I'm not even really sure of that. I don't want to get into an endless "will this one work?" loop, but there are of course thousands of different pressure measuring devices out there for different purposes.
  8. Feb 20, 2017 #7


    User Avatar
    Science Advisor

    Even if you have unknowns, you have to be able to put some ballpark numbers out.
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?
Draft saved Draft deleted