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MI-407 Series  Needle Electrode for pH (21 gauge)

MI-407 Series Needle Electrode for pH (21 gauge)


MI-407 Series Needle Electrode for pH (21 gauge)

Tip Selections

When ordering, please specify the needle combination from the Selection.


    TOTAL LENGTH                             

     5.5, 6.5, 7.5 cm


    1 m  

    BODY (Outer Diameter)

    6.5 mm

    TIP (Outer Diameter)

    .75 mm


    10 to 15 seconds 

    (stirred solution)


    1.0 mm


    pH 0 to 14  


    -5°C to 100° C  


    TYPE: Solution & Electrode

    Need external

    reference probe


    Carefully unwind the tape and remove the probe from the protective glass tube.  The white translucent sleeve, which covers the hole, should be moved down the glass barrel slightly to ventilate the reference chamber and replaced after each use. 



    The probe can be held by hand when measuring pH.  It has been standardized in two (2) pH buffers.  Follow the procedure recommended by the manufacturer of your pH meter for calibrating your pH meter with our microelectrode.


    OPTIMUM RESPONSE TIME will be obtained after the probe has been exercised in two (2) buffer solutions. 


    • Fill one beaker with a pH 4 buffer or equivalent and a second beaker with a pH 7 buffer or equivalent. 
    • Hold the microelectrode and touch the pH 4 buffer surface allowing 5 seconds for equilibration, and then touch the pH 7 buffer surface in the same manner.  Do this several times. 

    Using any electrode in solutions containing protein requires the electrode be rinsed with an enzyme cleaning solution.


    After each use, we recommend cleaning our electrodes with Terg-a-zyme (Alconox, Inc.) or a chromic/sulfuric acid glass cleaning solution by submerging the electrodes for a couple of minutes in order to remove all protein from the glass and reference junction.


    This will prolong the useful life of the electrodes.


    Always clean the microelectrode before storing:


    • Long-term (over 2 weeks): Return the probe to its original container and prepare it in the same condition in which you received it.  Usually this means simply moistening the sponge located in the bottom of the protective glass tube with pH 4 buffer.


    • Short-term: The probe can be left in an acid pH buffer solution (pH 4.01).
  • Instructions pdf

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