Penetrascope hardness tester documentation? Old school cool.
Close
Login to Your Account
Results 1 to 5 of 5
  1. #1
    Join Date
    May 2013
    Location
    Hermantown MN
    Posts
    262
    Post Thanks / Like
    Likes (Given)
    112
    Likes (Received)
    63

    Default Penetrascope hardness tester documentation? Old school cool.

    Hi, I recently got a Penetrascope Mk.VIII portable hardness tester.
    I've gathered all of the patent information I could find and I've written to Advanced-Coating in Belgium requesting information but have gotten no response.
    I understand how it works but do not have any table or charts detailing what force is to be applied to the penetrator nor a chart correlating the diameter of the impression to a hardness value.
    Does anyone out there have this information?
    There is a firm in Mexico which can supply new Penetrascope penetrators but since I already have several new Brale penetrators was wondering if I could adapt these to the Penetrascope?
    Thank you for any information.

  2. #2
    Join Date
    Jan 2014
    Location
    louisiana
    Posts
    443
    Post Thanks / Like
    Likes (Given)
    49
    Likes (Received)
    160

    Default

    I checked my manual stash, and I have a rockwell one, but no pentascope one.

  3. #3
    Join Date
    Apr 2004
    Location
    Shandaken, NY, USA
    Posts
    4,441
    Post Thanks / Like
    Likes (Given)
    1299
    Likes (Received)
    7288

    Default

    What does the hardness scale on the instrument read in ? Pentrascope is a new one on me. I am familiar with the old Shore Scleroscope hardness testers. These were the simplest of all, relying on rebound height of a hardened penetrating ball. The downside to the Scleroscope was it was strictly a surface hardness tester. Rockwell and Brinnell testers pushed the pentrating point into the work being tested and measured hardness a bit deeper. The Scleroscope was made in a portable version, and while the Scleroscope fell into disuse, the portable versions still see some use. Scleroscope hardness is correlated to Brinnell, Rockwell, and Vickers in various handbooks. I have never seen any reference to Pentrascope as a hardness scale. I'm curious to see what the instrument looks like. Maybe it is a re-make of the Scleroscope or used the Scleroscope principal ?

  4. #4
    Join Date
    May 2013
    Location
    Hermantown MN
    Posts
    262
    Post Thanks / Like
    Likes (Given)
    112
    Likes (Received)
    63

    Default

    Thank you Roll.

    Joe, from what I can ascertain the Penetrascope works much like a regular Wilson or Rockwell type tester in that you apply an initial load which pushes the diamond penetrator into the work a given amount. The tester is zeroed and then a full test load is applied and the penetrator goes a given distance further.
    With a Rockwell type tester the DISTANCE the penetrator travelled is measured to determine the hardness.
    With the Penetrascope a microscope lens is swung into position and the DIAMETER of the impression is measured using the eyepiece on the Penetrascope to arrive at a hardness figure.
    If I understand it correctly both Vickers and Brinnell testing methods require that the diameter of an impression be measured while Rockwell is the only one which uses penetration distance to arrive at a value.
    The big difference with the Penetrascope is the fact that loads are applied to the penetrator through a fluid medium and a tap off of this fluid chamber is routed to a large gauge which reads 0-50 kg. You set both initial load and test load using this gauge so knowing what values to apply for each portion is essential.

    Here is the auction I got this from and it shows some pics.

    Vintage England Apis Cabul Bracknell Berks The Penetrascope No MK VIII 736 | eBay

  5. #5
    Join Date
    Mar 2007
    Location
    On Elk Mountain, West Virginia, USA
    Posts
    2,109
    Post Thanks / Like
    Likes (Given)
    932
    Likes (Received)
    725

    Default

    Both Vickers and Brinnell hardness numbers are essentially load per unit area. If you can establish that the gage plus linkage in your machine will produce any actual known reasonable load, and the microscope will accurately measure the resulting indentation, using matching penetrator and formula you can measure hardness with it.

    MH describes the processes and formulas, as does Wikipedia.

    Nice score.

  6. Likes nsaqam liked this post

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
  •