Orion 8103BN ROSS Combination Semi-micro pH Electrode with BNC Connector, one model. The electrode, not the meter, is what decides whether a reading is right.
8103BN
Orion 8103BN ROSS Combination Semi-micro pH Electrode with BNC Connector. The electrode, not the meter, is what decides whether a reading is right.
An electrode ages from the day it is unpacked, whether or not it is used. The glass membrane hydrates and eventually degrades, the reference junction clogs with whatever it has been dipped in, and the internal electrolyte is consumed. A meter that reads badly is far more often carrying a tired electrode than a fault.
Budget for replacement on a schedule and keep the calibration record: a slope drifting away from 100% and an offset drifting away from zero are the two numbers that say when.
The junction is what matters most. A general-purpose ceramic junction suits clean aqueous samples and clogs quickly in anything else. A sleeve or flowing junction survives slurries, proteins, tris buffers and plating baths. A flat surface tip reads a solid — paper, skin, cheese, soil — where a bulb cannot make contact at all.
Store the tip wet in storage solution — never in distilled water, which strips the reference electrolyte and shortens the electrode's life.
Supplied in one model.