degital vernier caliper ppt

1. DEGITAL VERNIER CALIPER

2. Introduction
The Vernier Caliper is a precision instrument that can be used to
measure internal and external distances extremely accurately. The
example shown below is a manual caliper. Measurements are
interpreted from the scale by the user. This is more difficult than using
a digital vernier caliper which has an LCD digital display on which the
reading appears. The manual version has both an imperial and metric
scale Gauge Blocks .
Manually operated vernier calipers can still be bought and
remain popular because they are much cheaper than the digital
version. Also, the digital version requires a small battery whereas the
manual version does not need any power source.

3. History
• Modern technology is quickly revolutionizing how researchers and illustrators in the natural sciences go
about their work. Much of this results from the development of new methods for the scanning, digitizing,
and measurement of objects.
• Among the most popular of these devices are electronic calipers that combine the ease of use and higher
accuracy of digital calipers with a direct connection to the personal computer, generally through the serial
(RS-232) or Universal Serial Bus (USB) port in the back. Digital calipers provide accuracy of 0.001 mm or
better. Electronic calipers then took this a step further by providing not only the digital display but also in
allowing the information to be sent directly to the calipers. The whole system can be run by small batteries.
This makes electronic calipers transportable and their use flexible while they retain very high levels of
accuracy and repeatability. Current programs allow the data to be sent directly to destination programs such
as spreadsheets or database.
• If many measurements will be referred to repeatedly, electronic caliper systems provide a useful way to take
and store data more quickly and accurately than with digital calipers alone. If caliper use is infrequent, digital
calipers may be the most efficient option.
• Digitizing is the process of translating an analog world into the digital from recognized by computers. There
are two major approaches: point digitizing and scanning. Both are used extensively for natural science
research and , consequently, should be useful for illustrators.

4. • Point digitizing occurs whenever the two-or-three-dimensional coordinates of selected points are taken one-by-one and
stored. These can be individual points that are part of lines or surface. The accuracy of two-dimensional digitizers typically
is 1000 lines per inch or better. Most digitizers work by having two groups of densely packed wires, one at right angles to
the other, under a plastic or glass cover—the digitizing surface. A stylus (pen-like device) or cursor (puck-like structure
with cross hairs) is used to digitizing the points of interest. The digitizing pad determines which sire of each of the two
sets is closest to the position of the point of the stylus or cross hairs of the cursor. These two wire reflect the x- and y-
coordinates of that position. Buttons on the stylus (typically one or two) or cursor (3, 4, 12 or more) allow the user to
select different options while digitizing. A stylus is very useful for sketching , drawing, and digitizing single or smaller
numbers of points at any one time and tend to be much more accurate. They usually are much less effective for drawing
or sketching, although some illustrators prefer them. Pad sizes range from 6 in. *6 in. (15cm) to cover 3 ft* 4 ft (0.9m
*1.2m), with the most popular sizes being 12in. *12in.(30cm). Most are opaque, but transparent or translucent surfaces
also are available to allow underlighting, especially useful for x-rays and some tracing. In some cases, digitizing pads are
used as a substitute for a mouse, although most users have both for convenience.
• Digitizers excel at high-resolution input of spatial data. CAD (computer aided design) programs rely on digitizers as a
primary tool for gathering data because they do extremely well at high-resolution copying of existing plans, drawings, or
sketches. However, they tend to be less effective than a mouse as a primary pointing device. For illustrators, they will have
major uses for sketching directly into graphics packages and for development of models in CAD programs , which then can
be developed into maps, diagrams, blueprints, and three-dimensional models.
• Because gaging is a vital part of statistical process control (SPC), a new generation of electronic instruments has been
produced. These instruments incorporate a liquid crystal display (LCD) and are capable of interfacing with a data
collection device. Both inch and metric units are incorporated in one tool. The electronic feature is available on calipers,
height gages, depth gages, and micrometers.

5. CALIPER
• Vernier Calipers are commonly used in automotive industry as a
measurement tool for inspecting various parts in the auto industry.
There are two different and basic types of vernier calipers i.e. digital
and analog. The Digital Vernier Caliper
• (sometimes mistakenly known as Digital Caliper) is accuracy
measurement instrument that is utilized to measure external and
internal distances extremely perfectly. Below given example is a
digital caliper as the length measurement, are read from a LCD
display. The most important parts have been labeled.

6. PREVIOUSLY
• In old versions of this type of measuring instrument; a person has to
read by looking carefully at the imperial or metric scale and good
eyesight is also required to see the value of the measurement
correctly. People still use the old manual version of Vernier Caliper
and therefore it is yet popular because of its low price than the costly
digital caliper. Furthermore, a small battery is necessary
• for the digital caliper but the manual version does not depend on any
power source.

7. MEASURING EXTERNALITIES OF OBJECTS
• In order to measure the external distance place the object between
both external jaws and then carefully brought both jaws together,
then the digital display can be read

8. • Use the internal jaws of the Vernier Caliper which is present at the
head of the caliper inside the hole you want to measure. Then the
LCD will display the measurement.
• Digital caliper makes measurement easy. The foundation of the
Vernier caliper resides on the top of the hole and the depth
measuring blade is adjusted until it touches the bottom of the hole.

9. Instructions
• Before using the digital caliper for the first time, wipe clean the
surface with dry and clean soft cloth
• Always keep the digital caliper clean and dry
• Never apply electrical voltage onto any part of the digital caliper
• Do not engrave the caliper with electrical engraving pen
• Remove battery if the caliper is not used for prolong period

10. Nomenclature
1. Step measuring faces
2. Inside measuring faces
3. LCD display
4. Inch / mm conversion switch
5. Slider clamp screw
6. Beam
7. Scale
8. Depth measuring blade
9. Thumb roller
10. Battery compartment lid I I . Zero switch
11. Power ON / OFF switch
12. Outside measuring faces

11. Operation
Preparation:
• Wipe clean the measuring surface of the digital caliper with dry and clean soft cloth
• Loosen the locking screw and check if all the buttons, switches and LCD display respond
well
Basic Methods of Measuring:
• Make sure the slider clamp screw (5) is loosened
• Press the "ON" button (12) to switch on the unit
• Press the "inch / mm" button (4) to select the unit of measurement
• Close the measuring jaws and press the "ZERO" button (11) to reset the display to zero
• Use one of the following measurement methods to take measurement

12. Technical Specifications
• Display : LCD Type
• Measuring Speed : 1.5 m / seconds or 60 inches seconds
• Measuring Range : 0 to 150 mm / 0 to 6 inches
• Power : One 1.5 V button cell (Type Sr44)
• Storage Temperature : 0°C to 50°C / 32°F to 122°F
• Working Environment : 5°C to 40°C / 41°F to 104°F
• Resolution : 0.01 mm / 0.0005 inches
• Accuracy : +0.02 mm / ±0.001 inches (<100 mm)
: ±0.03 mm / ±0.001 inches (100 to 150 mm)

13. Fig 1. Typical digital vernier caliper Fig 2. Electronic assembly after dismantling the
plastic casing