Vernier principle

There are several possible explanations, but one simple mechanism based on the vernier principle is as follows. Two rod-like proteins of different lengths aggregate in parallel to form a linear complex (Fig. 5-4). This will grow until the ends of each rod exactly coincide. Now that there is no overlapping segment the complex will grow no further. 

Besides homologous series based solely on the vernier principle, cylindrites and franckeites also represent a homologous series resulting from variation in the thickness of the T layers [(1(X)) galena type]. Addition or subtraction of atomic sheets to or from these will appreciably alter the ratio MS/MS2 of the crystal as a whole, and the ratio (Pb -I- Ag)/ Sn. If the ratio of the total volumes of the T and H layers in cylindrite is denoted by r (= y) then in the other known phases the corresponding ratio varies from 0.66r in phase through 1.5r in incaite (Table 4 approximately... 

A high resolution can also be obtained if two delay lines with slightly different gate delay are used, i.e. a Vernier principle is applied [146]. The principle is shown in Fig. 4.14. 

Fig. 4.14 Vernier principle. The gates B1 to Bn are slightly faster than the gates A1 to An...

Vernier principle A method to assemble multitopic binding parmers (i.e., hosts or guests having distinct and uneven numbers of complementary binding sites) into a supramolecule of well-defined dimensions possessing the maximum number of complementary binding interactions. 

Thus we have studied the structure of the Y O iF +2 and Ba-Fe-S systems as typical examples of the vernier structure. In the vernier structure, the deviation from stoichiometry originates from the coexistence of different unit dimensions of the subcells, i.e. Aj and Aj sheets for the Y-O-F system, and Fe2S4 and Ba subcells for the Ba-Fe-S system. The structural principle of the vernier structure can be extended to a more general one, called adaptive structure , in which independent, though mutually related, structures for all the compositions can exist in a limited composition range (see Section 2.6). 

The most common instrument using the above principle is the vernier caliper (see Fig. 6.4). These instruments are capable of external, internal, step and depth measurements (Fig. 6.5) and are available in a range of measuring capacities from 150 mm to 1000 mm. 

The above principles apply to the vernier height gauge, Fig. 6.9. In this case the beam, carrying the fixed scale, is attached to a heavy base. The vernier scale carries a jaw upon which various attachments can be clamped. It is most widely used with a chisel-pointed scribing blade for accurate marking out, as well as for checking... 

The vernier caliper does not comply with this principle (Fig. 6.2). To ensure greatest accuracy of measurement, the workpiece being measured should be moved as close to the main beam as possible. The vernier depth gauge, however, does comply with Abbe s principle. 

Vernier calipers Large measuring range on one instrument. Capable of internal, external, step and depth measurements. Resolution of LCD model 0.01 mm Resolution 0.02 mm. Point of measuring contact not in line with adjusting nut (Abbe s principle). Jaws can spring. Lack of feel. Length of jaws limits measurement to short distance from end of workpiece. No adjustment for wear... 

The retarded vernier, similarly, has 10 divisions for an interval of 11 parts. The end of the object to be measured is lined up with the zero, so that in the advanced vernier example 22.17 + (0.7 x 0.9) is 22.80, exactly, for the match at subdivision 7 of the vernier. The retarded vernier example shows that 24.67 - (0.7 X 1.10) = 23.90 exactly, for the match at subdivision 7 of the vernier. The angular vernier has 30 minute divisions. Its principle is to be worked out as one of the problems at the end of the chapter. The angular vernier can be coupled with a micrometer screw for an even more precise length measurement. 

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