. Carnegie Institution of Washington publication. 108 EXPERIMENTS WITH THE DISPLACEMENT INTERFEROMETER. deflecting forces arising in the difference of potential of the quadrants. In the same way the negative effect, as regards sensitiveness, of an increase of the potential of the needle above a certain value is accounted for. Table 13 contains data bearing on this inference. TABLE 13.—Needle II; quadrants II; steel frame. Needle at — AF AN AJV/A7 I. 126 volts volt cm. ^2 cm. II. 150 volts • OS .040 .80 III. 183 volts .02 5 .000 .36 •05 •075 .100 .025 •047 .062 •50 •63 .62 Thus the
. Carnegie Institution of Washington publication. 108 EXPERIMENTS WITH THE DISPLACEMENT INTERFEROMETER. deflecting forces arising in the difference of potential of the quadrants. In the same way the negative effect, as regards sensitiveness, of an increase of the potential of the needle above a certain value is accounted for. Table 13 contains data bearing on this inference. TABLE 13.—Needle II; quadrants II; steel frame. Needle at — AF AN AJV/A7 I. 126 volts volt cm. ^2 cm. II. 150 volts • OS .040 .80 III. 183 volts .02 5 .000 .36 •05 •075 .100 .025 •047 .062 •50 •63 .62 Thus the sensitiveness rapidly reaches a maximum when the potential of the needle is about 150 volts, after which it more gradually diminishes (see fig. 66, curve 6). Furthermore, in Series III, where the needle is at the highest potential applied, the sensitiveness seems to increase with the voltage measured. This, however, is merely the result of the fact that there is apparently a small fixed voltaic potential difference between the quadrants, even if they are nominally identical or in the connections. Thus in fig. 66, curve a, AV and A7V are pro-. volts VOliS portional within the inevitable errors; but the deflections begin with a differ- ence of potential of about volt. In measuring such small voltages electrostatically these voltaic differences become of serious moment. The maximum sensitiveness obtained is not as large as above, being but 40X10-* volt per vanishing ring. Finally, the water damper was removed, so that the needle was subject to air damping only. After a long trial it was necessary to abandon the work, as, in consequence of the excessive drift, measurement was out of the question. Most of this drift is probably intro- duced by the steel Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble t
Size: 1737px × 1439px
Photo credit: © Book Worm / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookauthorcarnegie, bookcentury1900, bookdecade1900, bookyear1902
