Results 1 to 5 of 5

Thread: What units is a vacuum gauge in?

  
  1. #1
    Status
    Offline
    Moffat's Avatar
    AOC Obsessed
    Join Date
    Sep 2006
    Posts
    1,678
    Mentioned in
    0 Post(s)
    Quoted
    0 Post(s)

    What units is a vacuum gauge in?

    When i was looking at my boost gauge earlier, i looked to the negative side of it, the vacuum half. The boost is measured in PSI, but the vacuum is in InHg. What does that stand for? Or how is it measured?
    Mk5 Astra 888 CDTI No.58
    "you can’t help but drive the 888 Astra hard, everywhere, constantly" - Evo Magazine.

  2. #2
    Status
    Offline
    Ffoeg's Avatar
    2170:01:06
    Join Date
    Jun 2003
    Posts
    34,591
    Mentioned in
    2 Post(s)
    Quoted
    0 Post(s)
    Odd that you've got a gauge that's marked off in two units. What make is it? any piccies?

    In Hg is Inches of Mercury - ie the vacuum needed to lift a column mercury up a tube by 1 inch

    1 psi = 2.036 In Hg (at 0 degrees C)

  3. #3
    Status
    Offline
    Moffat's Avatar
    AOC Obsessed
    Join Date
    Sep 2006
    Posts
    1,678
    Mentioned in
    0 Post(s)
    Quoted
    0 Post(s)
    It's an Autogauge one Geoff.
    This is the only quick pic i have of it, from when i first fitted it.


    In over-run, it usually gets as low as about 25 InHg's.

    Does that mean at that point, it's in vacuum equivelant to that of how much vacuum it would take to lift a column of mercury up a tube by 25 inches?

    Is mercury heavy?
    Mk5 Astra 888 CDTI No.58
    "you can’t help but drive the 888 Astra hard, everywhere, constantly" - Evo Magazine.

  4. #4
    Status
    Offline
    Ffoeg's Avatar
    2170:01:06
    Join Date
    Jun 2003
    Posts
    34,591
    Mentioned in
    2 Post(s)
    Quoted
    0 Post(s)
    Very odd

    Going by other gauges that they do, it looks like they've done it to make the face less clutered and the increments more evenly spaced (even tho it's two differing units).

    Here's one they do in bar for comparison


  5. #5
    Status
    Offline
    Harty's Avatar
    AOC Regular
    Join Date
    May 2007
    Posts
    113
    Mentioned in
    0 Post(s)
    Quoted
    0 Post(s)
    My boost gauge is in INHG and PSI aswel.
    Coupe Turbo coming soon!

    www.westmidsonline.co.uk

Similar Threads

  1. vacuum gauge help !
    By Rizla in forum East Midlands Region
    Replies: 0
    Last Post: 27-01-2013, 20:17
  2. vacuum gauge
    By mike_astrasport in forum Turbo Petrol Engines inc. Transmissions
    Replies: 3
    Last Post: 16-11-2008, 18:36

Posting Permissions

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