Similar results have shown up lately, in beetles, crickets, bees, grasshoppers and flies. The magnetic sense is so strong in many insects that they will rest only in definite "magnetic positions". The moths became so disoriented they left the property!
With this setup, a conservator is able to precisely regulate the flow of the current to the artifact and maintain a predetermined electrode potential conducive to metal reduction on the surface of the specimen.
This setup is used for artifacts that are especially significant and need to be conserved as carefully as possible. The Type 2 electrolytic setup Figure 10B. When this arrangement is used, it is important to make sure that the distance between the different anodes is greater than the distances between the artifact and its anode in order to prevent any cross-over current.
This point is not graphically depicted in Figure 10B. With this setup, the current flow to each artifact can be carefully controlled, and the correct electrode potential can be maintained. Since the chlorides present in the electrolyte come from all the artifacts in the vat, it is not possible to determine exactly when a specific artifact is chloride-free.
The chloride test does, however, tell the conservator when to change a chloride-contaminated electrolyte and when all of the artifacts are chloride-free. If an artifact requires close supervision i. The most critical variable for precision control is the ability to maintain an even current density on the cathode surface by positioning the anode equidistant from all parts of the artifact while maintaining a steady reduction electrode potential.
Monitoring the chlorides during electrolysis is of lesser importance. The most commonly used electrolytic setup involves connecting multiple artifacts to a single power supply. Regardless of how it is configured, Type 3 electrolytic setups Figure 10B.
In one configuration Figure 10B. The artifacts share common anode sheets placed above and below the specimens. An alternative variation of this setup has a common bottom anode and individual top form-fitted anodes to assure a more even distribution of the current to each artifact.
In the most popular Type 3 configuration Figure 10B. Adjustable vertical anode sheets are hung on either side of the vat, and another anode is laid along the bottom of the vat. The increased circulation also helps to maintain the anodes in a passive state by preventing the formation of strongly oxidizing, acidic hypochlorite from forming on them.
Sandwich setups have all of the disadvantages discussed above. An additional disadvantage is that the proximity of the object to the negative terminal connection is a factor in the current flow. The closer an artifact is to the negative terminal the more current it receives.
By regularly repositioning the artifacts, each object will receive an average current for the duration of the treatment.Start studying Chapter 6. Learn vocabulary, terms, and more with flashcards, games, and other study tools. Search.
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