Electrodes are a type of conductor that allows electrons to pass from a metallic part to a non-metallic part. The part where electrons enter the electrode is known as the "cathode," and the exit is known as the "anode." Due to their ability to effectively filter electricity from one source to another, electrodes are extremely versatile and several different types have been created to meet a wide variety of needs.
One of the most common types of electrodes is the welding electrode. Welding is the process by which two metals are melted together at extremely high heats in order to make a new, stronger metal. The melted-down metal is normally put into a welding rod, and it is this welding rod that is then used as the anode of an electrode. A welding electrode is a valuable part of the process because the electricity the electrode exerts can both speed up and strengthen the welding process.
Ion Selective Electrodes
An ion selective electrode only allows certain types of charged atoms (known as "ions") to pass out into the anode. Ion selective electrodes have a wide range of uses, such as measuring pH levels in water, reading electrical meters, or as part of experiments measuring the density of an atom in a specific compound or substance.
Auxilary, Working and Reference Electrodes
Multiple electrodes can be set up in a sequence so that electricity passes from one to the next, filtering out electricity or creating a further buffer from the original source. Typically these chains of electrodes come in threes, with the three electrodes being the auxiliary, working and reference electrodes. Any of these three can be used as an anode or cathode, depending on the setup.