Textbook of Engineering Drawing, Second Edition

(Jacob Rumans) #1

--------------------------Scales 3.11



  1. Draw a line of20 em length. Complete the rectangle of20 em x 0.5 em and divide it into
    4 equal parts each representing 1 metre. Sub divide all into 10 main scale divisions.
    1 msd = Im/l0 = Idm.

  2. Take 10+ 1 = 11 divisions on the main scale and divide it into 10 equal parts on the vernier
    scale by geometrical construction.
    Thus Ivsd= llmsd/lO= 1.1dm= llcm

  3. Mark 0,55, 110 towards the left from 0 (zero) on the vernier scale as shown.

  4. Name the units of the divisions as shown.

  5. 2.28m = (8 x vsd) + 14msd)
    = (8 x O.llm) + (14 x O.lm)
    = 0.88 + 1.4 = 2.28m.

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