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• Before assembling the electrode for the first time or reactivating it after storage, the inner
electrode assembly should be hydrated then tested as a pH electrode.
• Take two beakers and pour 50 mL de-ionized water in each of them.
• Add one powder packet of
HI 4000-47-4
pH 4 in one of the beakers.
• Add one powder packet of
HI 4000-47-7
pH 7 in the other beaker.
• Remove the protective shipping cap from the glass inner electrode. Handle the sensor by the
black cap, and use with care to prevent breaking the glass.
• Or unscrew the upper cap on the top of the electrode and carefully withdraw the internal glass
assembly.
Do not touch the sensing portion with your fingers.
• If the sensor has been stored/shipped dry, it should be “conditioned” by soaking the pH glass
in a small sample of one of the buffers, prepared above, for 1 hour or longer. Immerse the
glass tip in small sample of the buffer while supporting the upper portion in an electrode
holder. Take care that the glass is fragile.
• Connect the BNC connector on the cable assembly to a pH/mV (ORP mode) meter. Carefully
immerse the sensor tip into the buffer. Record the mV in each solution once the values have
stopped changing. Pay attention to minus sign if it is present.
• Rinse tip in deionized water and blot dry between buffers.
• Calculate the difference in mV between the two solutions.
• The ideal difference is 175 mV. Values greater than 180 mV are acceptable (90% efficiency).
INNER ELECTRODE CHECK
• Hold the probe vertically, unscrew the top cap and remove the glass electrode inner body from
the electrode outer body.
• Perform the inner electrode check.
• Unscrew membrane cap from outer body and install membrane using tweezers. Avoid touching
working area of membrane with your fingers as skin oil will change the hydrophobic
properties of the membrane. Discard paper backing between membranes. Drape membrane
over lower opening of outer body and hold one corner against the threads. Smooth excess
membrane material around the threads.
• Screw outer membrane cap onto body thus capturing the membrane between the cap and outer
body thread.
• Add 2 mL of Ammonia internal electrolyte
HI 4001-40
into outer probe body.
• Insert and position the internal glass part into the outer body so that the anti-rotation key sits
in the cutout on the outer probe body.
PREPARATION PROCEDURE