| 摘要 |
A Ag/AgCl electrode includes a rigid tube within which a Ag/AgCl conductor is mounted by epoxy. An insulated wire lead is coupled by a solder joint to the Ag/AgCl conductor. An optional plastic cap seals the upper end of the tube and the wire lead extends out of the upper end of the tube and through the plastic cap. A sodium chloride solution is provided in the lower end of the tube such that the conductor is bathed in the solution. The solution is maintained within the tube by a porous glass, ceramic, or polymeric plug which is press fit into the lower end of the tube. The lower end of the tube, including the plug, is coated with a water soluble non-toxic substance. The water soluble coating is preferably made from a concentrated solution of polyvinyl alcohol (PVA) in deionized or RO water which is preferably applied by dip coating and air drying. The PVA forms a hard durable protective coating which prevents the sodium chloride solution from dissipating during the time between manufacture and use of the electrode. In addition, the PVA quickly dissolves once in contact with flowing water.
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