Connect with us

black star multimeter 3225

Discussion in 'Electronic Equipment' started by g.knott, Oct 10, 2007.

Scroll to continue with content
  1. g.knott

    g.knott Guest

    Does anyone know how to calibrate this? Made in the UK.
     
  2. Jamie

    Jamie Guest

    First you sit down and eat your tea and crumpets.
    then you complain about the price of petrol.
    then you complain about the Americans. ( that is if you
    are a Brit to start with). and after all of that.
    if you still have interest in calibrating that meter.
    You could then start looking at the manual.
    personally, I don't thing the meter should nerd
    calibrating. If so, and you're looking for very high
    accuracy? I don't think you should be doing it.

    Over here in good old USA. a Simpson 260 Analog
    meter is considered a standard. Or at least, it once
    was. ( I have one btw, in very good condition)
     
  3. g.knott

    g.knott Guest

    Ah another helpful American ;-)

    The point is that I have a class of students that must calibrate a piece
    of electronic equipment according to the manufacturer's instructions.
    We have lots of these meters and since they are battery driven they are
    safe to dismantle.
    I was hoping someone has done this.
     
  4. Robert Baer

    Robert Baer Guest

    Well, if you really want to "calibrate a piece of electronic
    equipment according to the manufacturer's instructions" thenyou need to
    get those instructions.
    And since you are referring to a mass production unit, any
    calibrating (pot tweaking) done at the factory is done according to
    *internal* methods and thus is !proprietaty! and will not be disclosed.
    So, the best you can do in this case is "calibrate a piece of
    electronic equipment according to best (to be determined) efforts".
    Take one apart and tweak only one pot at a time, say by only one
    screwdriver blade-width, and check all scales to find what changed.
    This way, each adjustment can be labelled "capacitance zero",
    "resistance", "voltage", "unknown".
    *RESET* the tweak when done.
    Use a digital camera for a closeup and label the photo (use arrows to
    pots) accordingly; print copies along with a suggested procedure that
    you determine.
    You can use 0.1% resistors and 2% capacitors as "standards", along
    with an off-the shelf precision voltage regulator.
    Current measurements are never adjustable; they depend on the
    internal shunt accuracy and voltage measurement accuracy.
     
  5. Jamie

    Jamie Guest

    Ok, well, I do remember (years ago no when I was a kid), a fresh carbon
    cell was to output something like 1.56xxx , I can't remember exactly.
    but that was the calibrator. Now days, I really don't think they do that
    any more.:)
    Sorry I couldn't of been any more help to you.
     
  6. g.knott

    g.knott Guest

    Thanks.
     
  7. Robert Baer

    Robert Baer Guest

    No, no, no!
    Mercury cells were good enough to use as a secondary standard when
    calibrated, and if not, new ones wer good to 5 digits (if i remember
    correctly - been ages).
     
Ask a Question
Want to reply to this thread or ask your own question?
You'll need to choose a username for the site, which only take a couple of moments (here). After that, you can post your question and our members will help you out.
Electronics Point Logo
Continue to site
Quote of the day

-