Milwaukee SE220 replacement electrode
The electrode (shown in picture) on the Milwaukee MW102 pH meter is replaceable. Once the readings start to jump around and not stabilize, it's time to replace the electrode.
Do not purchase spares as the tip must be kept wet at all times. While they come packaged with a damp sponge, if left too long they will dry out. For the same reason it's recommend that the replacement be purchased by a retailer who moves a lot of stock and doesn't have electrodes sitting around on shelves in (possibly) hot warehouses.
For complete details see our Measuring pH article.
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