Thermo Fisher Scientific EC620130 Series Combination pH Electrodes - Manual (Page 3)

www.thermofisher.com
at low pH or in the presence of organic solvents. -133 offers a rugged spear tip is ideal for semi-solids or
soft foods.
GETTING STARTED
Each electrode has a unique serial number and is quality checked before it leaves the factory.
Electrodes are shipped with an electrode storage bottle containing electrode storage solution. This
storage solution will occasionally creep out and appear as dry white crystal residue on the electrode.
However, this will have no long-term effect on the electrode and can be simply rinsed off with clean
water.
Proper removal and insertion of the storage bottle is very important. Improper use can result in a
pressure build up either inside the electrode or the bottle resulting in electrolyte leakage through the fill
hole or the cap of the storage bottle. Proper use of the electrode storage bottle is shown in Figure 1.
EC-620-130 is a refillable electrode and will include a bottle of Skylite electrolyte solution along with a
separate syringe and nozzle for electrolyte refilling process. New electrodes are shipped filled with their
filling holes closed, so electrolyte refilling of a new electrode is generally not required. It is recommended
that the Skylite electrolyte (EC-636-430) be added using the syringe and nozzle provided when the
electrolyte level in the reference cavity (outer annular space) is lower than ¼ inch below the cap. Simply
open the fill hole at the top of the electrode by rotating the cap ring. Mount the nozzle to the syringe and
fill it with the Skylite electrolyte solution (The tip hole of the Skylite bottle can be enlarged by trimming
the tip so as to accommodate the diameter size of the nozzle during electrolyte collection into the
syringe). Insert the syringe’s nozzle into the fill hole of the electrode and gently inject the electrolyte into
the electrode. If the electrolyte level is not visible, the electrode may be filled to a capacity just beneath
the fill hole.
NOTE: EC-620-130 has a faster electrolyte flow rate as compared to other conventional refillable electrodes.
Therefore a fast drop in the level of its electrolyte will be observed and this should not be construed as a sign of
an electrode problem.
Mount the EC620130 series open-pore electrodes onto a suitable electrode holder and connect the
electrode to the meter. For EC-620-130 refillable electrodes, the fill hole should be in the open position
when in use. If necessary, rotate the cap ring to open the fill hole.
Immerse the electrode in pH 4 or pH 7 buffer for 5 to 10 minutes to condition the glass pH bulb.
ELECTRODE OPERATION
1) The level of electrolyte in the outer cavity should be kept above the level of the solution being
measured to prevent reverse electrolyte flow. The electrode needs only be immersed far enough to cover
both the glass pH sensing bulb and reference junction to obtain accurate readings.
2) If the electrode has not been hydrated (placed in solution for more than one hour), allow the
electrode to soak in a buffer (preferably pH 4) as needed prior to standardization or measurement. This
will help to optimize and re-establish the thin hydration layer on the sensing bulb that is critical to
accurate pH measurement.
3) Rinse the electrode with deionized or distilled water between samples. Note: wiping the sensing bulb
is not recommended as the thin hydration layer of the sensing bulb could be affected and electrical
charges may be produced.
4) Moving or touching the electrode cable may result in unstable readings due to the high impedance
(resistance) of the pH glass membrane.