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Metrology - simulator

Virtual Dial Indicator, simulator in hundredths of
millimeter - 0.01mm - use, reading and understanding


roll down the page to interact
with the dial indicator simulator
Simulator of reading and understanding of Dial Indicator - how to use this instrument of linear measurement

The Dial Indicator, some times called Prob Indicator, it is one of the few analog measurement instruments that allows the measurement of linear measurements directly (by measuring directly the desired) or indirectly (establishing the difference between the desired measurement and another known).

In this simulation you will learn the science of using this measuring instrument, interacting with the spindle or the contact tip ( see main components). In this learning object, you can also turn the 'display' (dragging and dropping the hoop in a circular motion) so that the line 'zero' align with the pointer after the called ' preload ', hide the measure provided (by clicking the eye icon) and cancel the spring effect of the instrument (by clicking the 'lock').

 

Dial Indicator and your utilization

This instrument of measurement works fixed to devices devices such as bases, supports, or guides. Because of its fragility, we do not recommend its use in the operator's hand.

Dial Indicator and the directly measurement (indicator)

By definition, directly measurement (or indicator) occurs when the value of the wished measurement (mensuring it) is read directly in the device display of the measurement instrument. For example, when we determine a linear dimension with a paquimeter ( see the paquimeter simulator ), the reading that we obtained in the scale and it's vernier , not considering errors, is the efective measure of the object that we are submiting to measurement.

We use this dial indicator on this mode of measurement together with surface plate and(or) supports to measure the thick plates, for example, among other measures relatively small.

This method of utilization is seen in the Simulator and at figure 1. We submitted the instrument to a preload , we setted to zero mark (turning the counter), we moved the spindle mannually giving space to put the object to be measured in the axis of the instrument and return the spindle until the contact with the part that holds it. The dimension is read directly in the counter, by relative position (displacement) of the main pointer and of the turns counter.

Dial Indicator and the indirect measurement

On this case, by contrast, we have indirect measurement (indicator), when the read value in the display device of teh instrument it is not the value of the measure that we are mensuring. For example: when we use a barometer, or we measure the shadow, to determine the height of a building.

One of the possible uses of the dial clock compartator is to calculate the difference between a pattern and the one of we are mensuring.

Dimension of part = pattern dimension + (or) - value read in the instrument

We adjusted to zero the instrument with a pattern that dimension is known and we stablished the difference between her and of teh object that we are submting to measurement, algebraically -figure 2.

Dial Indicator and the mechanic of it's reading

Using a dial indicator is one of the most easy tasks of metrology. We will understand the method using as example the simulator e you will get to use a lot of other models, with it's scales, ranges and resolutions. In general, they come with notes printed in the display showing your resolution and the nominal range (ex: 0.01 - 10.00mm or 0.001 - 1.000"). ( to interact with the Simulator of the Dial indicator in milesimal inch (1.000") click here)

One complete turn of the main pointer of our simulator it represents one millimeter of spindle. The display has ten numered divisions (from 0 to 90, ten by ten) and each of it is subdivided by ten, in a total of a hundred (100) dividions. This way each of the traces of teh display it represents to hundredeth part of millimeter (0.01mm) -figure 1. The nominal range of teh instrument of figures 1 and 2 is 10mm (to solve the limitations of the monitors resolution, the nominal range of this Simulator of Dial Indicator is 1.14mm - Click here and interact with a simulator of dial indicator with realistic path and nominal range of 10mm ); this carachteristic turns necessary that some device count the number of turns of the main poiter (number of integer millimeters to be added to the centesimal part).

Procedure to direct reading

Dial indicator in direct reading

figure 1 - dial indicator - direct measure

This step by step describes the procedures to the reading of figure 1. Observe thta the pointers are turning to opposite directions and the movement of the main pointer is the clockwise;

  • the instrument is fixed in a place that works in conjunct with a surface plate
  • touch the contact point in the surface plate and put the preload
  • turn the display until the trace with the zero (0) mark will be aligned with the pointer
  • read the initial condition of the pointers, comparing with the display
  • gently, stand up the spindle until you find space to the object of measurement
  • with the same care, return the spindle (propelled by a spring) until that it touch in the object of the measurement
  • read the pointer of the turn counter (small display), leia o ponteiro do contador de voltas (mostrador pequeno), subtracting the number of spaces between the traces that it runned into
    • 7-0 = 7mm
      • see that the pointer was perfectly aligned with zero in the beggining and later passed the line seven. That means that there is a centesimal part to be read.
  • read the main pointer to determine the centesimals
    • It passed through seven numbered lines (0.1mm each) and a small line when went away from zero and stopped in the last turn, like this: 7x0.1mm + 1x0.01mm = 0.71mm
  • sum the results
    • 7mm + 0.71mm = 7.71mm, that is the dimension of teh object that is being measured.

Procedures to indirect reading

Dial indicator in indirect reading

figure 2 - dial indicator - indirect measure

This step by step describes the procedures to the reading of figure 2, observe that the pointers are counter-rotating and the movement of the main is anti-clockwise. Do not forget that to indirect readings:

Dimension of the part =
Pattern dimension + (or) - Value read in the instrument

  • the instrument is fixed in a place that works in conjunct with a surface plate
  • touch the contact point in the surface plate and put the preload
  • turn the display until the trace with the zero (0) mark will be aligned with the pointer
  • read the initial condition of the pointers
  • gently
    • stand up the spindle
    • take off the pattern and
    • put in the object for measurement
  • with the same care, return the spindle until that it touch in the object of the measurement
  • read the pointer of the turning counter, subtracting the number of spaces between the ones that passed trough
    • 10-8 (the pointer movemented in the against direction of teh counter) = 2mm
  • read the main pointer to determine the centesimals
    • it passed trough two numbered lines (0.1mm cada) and nine small lines when started from zero and stopped in the last turn, like this: 2x0.1mm + 1x0.09mm = 0.29mm
    • another way to read this thing is: 100/100-70/100 = 30/100+1/100 = 0.29mm
      • see that the pointer passed trough the tenth parts in the opposite direction of the counter, so, use (-), however, the pointer didn't get into the 70 hundredths, missing one hundredth, so, sum (+) 1/100
  • sum the results
    • 2mm + 0.29mm = 2.29mm
  • subtract this result from the value of the dimension gauged by the pattern (the direction of the rotation of the pointers) counter-rotating, indicates that the object is smaller comparing with the pattern
    • 10mm - 2.29mm = 7.71mm
Turning display of dial indicator to zero mark

figure 3 -
dial indicator - aligning zero of the display

Turning display to zero mark

After stablishing the preload , the dial indicator it has a hoop that allow turning the display to, for example, align the zero of the Main Pointer to facilitate the reading, and for that it's needed to realease the screw that holds the hoop.

Dial CIndicator Components

Click here to explore a image of a dial indicator and know the name of its main components.

after interacting with the virtual dial indicator, I recommend that you solve this
list of exercises of reading and interpretation of the dial indicator in millimeter in centesimal resolution (0.01mm)

Virtual Dial Indicator:
Simulator of use, reading and interpretation of the Dial indicator

In the Dial Indicator below, drag and drop, in the vertical, the orange highlighted detail for reading

tips:
- turn the bigger display of the dial indicator
- click in the icon 'eye' to hide the measure
- click in the icon 'locker' to cancel the effect of the spring of the instrument

note: by limitations imposed by the resolution of the monitor, the distance runned by the the contact tip is not proportional to the indicated measure

thank you note:
to the amateur photographer Murilo Photo and his contribution comming diretly from Toyohashi, Aichi, Japan, (2010).
Eduardo J. Stefanelli - www.stefanelli.eng.br