pH Meter Calibration Help

Discussion in 'Darkroom Equipment' started by Smudger, Jan 26, 2013.

  1. Smudger

    Smudger Member

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    I have just acquired a cheap meter,and need some help.
    I need to prepare 200ml of pH4 solution. I have Sodium Hydroxide,Reagent-Grade pellets,"Not less than 97% Pure,Mol Wt 40.00".
    How many grams of this will make up to 200ml of pH4 ?
     
  2. Prof_Pixel

    Prof_Pixel Member

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    Like the old saying goes, "You can't get there from here". A pH of 4 is acidic; there is no way a NaOH solution will be acidic.

    Calibrations are usually made with buffer solutions. See http://en.wikipedia.org/wiki/Buffer_solution for more info.
     
  3. drumlin

    drumlin Member

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    You will need buffer solutions. They can be prepared, but you are MUCH better off looking for a small set of pH 4,7,10 buffers (provided that's the range you're working in).

    May the force be with you.
     
  4. DREW WILEY

    DREW WILEY Member

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    Any lab supply can supply you with buffers solutions. You also need to have some distilled water on hand.