Metrology - simulator

Use of the vernier caliper - four-dimensional

Use of the vernier caliper - four-dimensional

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The vernier caliper is one instrument of measurement dopted of one scale and a cursor that slides in itself and it was concebed to take linear dimensions by contact.

The most popular type in the metal-mechanic offices is the one dopted of vernier, but, usually, all kinds alows to take external, internal, depth and rebound meausres.

To comprehend the science of the measurement with caliper, we suggest you to read and to interact with the simulators in the pages:

Simulator of reading nd interpretation of vernier scale in millimeter, tenth resolution

Virtual vernier scale - simulator of use and reading, resolution five hundredths of millimeter 0.05mm

Use of vernier caliper - four-dimensional

Some caliper models are four-dimensionals, this means that it can be used in four different ways in the measurement. See some examples of best practices:

Procedure to take a measure

  1. open (separate the contact faces) the caliper a little bit more than the object to be read
  2. put the object in the aperture
  3. gently close it until there is contact between the faces and the object
  4. be sure to align in paralel, you can do that with a gently balance movements
  5. make the reading and interpretate the measure
  6. open the caliper and take of the object
  7. place both in an adequate local
  8. repeat the operation to confirm the measure

evidently, it is necessary to adpat this procedure to each kind of measurement, for example, it is possible to move the caliper before the reading in depht or rebound measures, or to internal or external measures. The first step is to open the instrument a little bit less that the hole to be meausured and the 6th step is to close the instrument before removing it from the hole.

External measurement

example
universal vernier caliper - external measurement

figure 1
best practices of external measurement with vernier caliper

counterexample
universal vernier caliper - external measurement

figure 2
external measurement -
object very far from scale

Gently, close the caliper and press the faces of the backrests fixed and movable against the paralel faces, or diameter, of the distance you intend to measure, figure 1.

Alow the caliper to align with the object that is beeing measured. This is possible holding them together without tightening.

Place the object close to the main scale, no touch in there, figure 2

Internal measurement

example
universal vernier caliper - internal measuring

figure 3
best practices of internal measurement with vernier caliper

counterexample
universal caliper - internal measuring

figure 4
internal measurement - object very far from cursor

Gently, open the caliper and press the faces of the ears fixed and movable against the paralel faces, or the hole that you intend to measure, figure 3.

Alow the caliper to align with the hole or rip that is beeing measured. this is possible holding them together without tightening.

Place the object the most close possible of the cursor, conterexample figure 4.

Depth measurement

example
universal vernier caliper - depth measurement

figure 5
depth measurement with vernier caliper

Hold the top of the main scale of the caliper in the surface of the piece, open it and, gently, press the top of the rod of depth against the end of the hole or rip that you intend to measure, figure 5.

Alow that the rod remais in paralel with the hole or rip that is beeing measured. This is possible holding them together without tightening.

Depth measurement - conical bottom hole

example
universal vernier caliper - depth measurement

figure 6
best practices of internal measurement with vernier caliper - drill hole

counterexample
universal vernier caliper - depth measurement

figure 7
measure of drill hole - rod measuring part of the cone

Take care to don't lose the refference, use the side of the rod of depth with no slot, figure 6.

If you use the side with slot, the top of the rod will go until take place in the cone of the drill point, adding a few more tenths of millimeter to the measure, figure 7.

Depth measurement - furo de fundo cego

example
universal vernier caliper - depth measurement

figure 8
best practices of internal measurement with vernier caliper- drill hole

counterexample
universal vernier caliper - depth measurement

figure 9
measure of blind hole -
rod measuring burr

To measure the depth of one blind hole, use the side of the rod with the burr, figure 8. This practice avoid round measurement of the botton.

Rebounds measurement

example
universal vernier caliper - Measuring rebounds

figure 10
measurement of rebounds with vernier caliper

Some caliper companies have added one caractheristic very interesting, that alows the measurement of rebounds. The top of the cursor and of the main scale are coplanar. This way, it can be used much greater accuracy than that obtained when using the depth rod, figure 10.

Use of vernier caliper - four-dimensional

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Eduardo J. Stefanelli - www.stefanelli.eng.br