The life of a pH electrode is not infinite. A number of factors affect
the life span of a pH electrode. The higher the temperature that the electrode is used
at, the more extreme the pH, how often the bulb dries out and needs to be
rehydrated, how roughly it is used; all these factors and more shorten the life span of an electrode. An electrode that is well maintained and cared for can last up to 2 years, one that
is not well maintained will not last as long, and one that is well maintained will
not last significantly longer.
Storage of the pH electrode
when not in use.
The pH electrode bulb needs to be moist at all times. When you are done
with the electrode pour electrode storage solution into the cap that came with
the electrode and put the cap over the bulb of the electrode. Keep the cap on until next use.
If the electrode is being stored for a long time you may want to check the cap to be sure
the storage solution is still in the cap and keeping the bulb moist. DO NOT STORE THE pH ELECTRODE IN DISTILLED WATER. Storing the pH electrode in
distilled water will shorten the life of your pH electrode.
If you do not have electrode storage solution use pH 4 buffer solution.
If you have neither electrode storage solution or pH 4 buffer solution you can use pH 7
buffer solution for a short time.
Rinsing the pH electrode
between measurements.
You should rinse your pH electrode between measurements. This can be
done with distilled water or rinsing with a sample of the next solution to be
measured. Using both distilled water and then a sample of the next solution is also a good
way to rinse the pH electrode between measurements.
pH electrode fill hole
Some pH electrodes have a fill hole for refreshing the electrolyte in
the pH electrode; other pH electrodes do not have a fill hole. If your pH electrode has a
fill hole the fill hole cap should be removed during calibration and use. This allows for the
correct amount of reference electrolyte to flow into the sample. Replace the fill hole
cap when done with the electrode at the end of the day
If bulb dries out, soak
electrode bulb in pH 7
pH electrode bulbs should be keep moist at all times. When not in use
the pH electrode bulb should be keep moist by pouring electrode storage solution in the
cap provided. If the pH electrode bulb does dry out, soak it in pH 7 buffer for a couple
of hours before calibrating or taking measurements.
Do not wipe the pH electrode
with a cloth or any other type of material.
When you are done with the pH meter rinse off the electrode with
distilled water, put storage solution in the cap, and put the cap on the end of the pH
electrode as described above. If the electrode is wet do not dry it off, let the distilled
water evaporate by itself.
Cleaning the pH electrode
The pH electrode needs to be cleaned in order to prevent build up of
material on the surface of the glass bulb. How often it needs to be cleaned depends
upon frequency of use and the material being tested. An electrode used on dark coloured
and viscous material usually needs to be cleaned more often than an electrode used on clear
thin material. Material building up on the glass bulb of the electrode will cause the
calibration of the electrode to be inaccurate and any subsequent reading to be inaccurate.
Follow the instructions supplied with the electrode cleaning solution when
cleaning the electrode bulb.
P&R Labpak supply a wide range of electrode storage solutions, buffers and other associated accessories from all major manufacturers including Hanna Instruments, Mettler Toledo, Sentek, Jenway, Schott, WTW etc...
Visit www.prlabs.co.uk or call us on 0870 034 2055.
No comments:
Post a Comment