CLASSIFICATION OF LIMIT GAUGES
RING GAUGE:
A ring gauge, or ring gage, is a cylindrical ring of a
thermally stable material, often steel, whose inside
diameter is finished to gauge tolerance and is used for
checking the external diameter of a cylindrical object.
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Dial Gauge:
– Dial gauges or Dial Test Indicators are used for
checking flatness of surfaces & parallelism of bars &
rods
– They are also used for testing the m/c tools
– They can also be used for measurement of linear
dimensions of jobs which require easy readability &
moderate precision
STANDARDS
• Standards is a norms or specification of a method, material or
a product.
STANDARDISATION
• Process Of Standardization is the Setting Up Standards.
• Example : Bolts are available In Standard Sizes as 10mm,
12mm etc.
• The Electric Bulbs are Specified as 15 Watts,40 watts etc.
• The Electric Supply Voltage in house is 220-230 Volts.
CLASSIFICATIONS OF STANDARDS
• Company standard
• Industrial standard
• National standard
• International standard
COMPANY STANDARDS
• A company standard is set up and used in that particular
company only.
• This standard is set up by common agreement between
various departments of the company.
• This standard is used for design, purchase, manufacture
and other operations.
INDUSTRIAL STANDARDS
• Some manufacturing companies join together and
set up standards. This is called industrial standard.
• The companies make use of this standard for their
activities.
NATIONAL STANDARDS
• National standard is set up for use in that particular company
by a national organizations.
• In India, the national standards are set up by the bureau of
Indian standards.(previously it was known as Indian standards
institution-ISI).
• Almost all industrial companies in India follow the Indian
standards in their manufacturing activities.
INTERNATIONAL STANDARDS
• This standard is set up by an international standard
organization.
• Many countries in the world follow this standard by common
agreement between them
• These countries fix their national standards similar to
international standards for many of their products and service.
• By this it becomes possible to exchange goods and services
between various countries.
• Mutual cooperation in the sphere of scientific, technological
and economic activities is resulted between different nations
BENEFITS OF STANDARDISATION
• Benefits to the manufacturer.
• Benefits to the customer.
• Benefits to the sell of goods.
BENEFITS TO THE MANUFACTURER
• Mass production of products at cheaper cost. This is because of
simplified inspection procedure, reduction in repair & maintenance
cost.
• Reduction of stocks and inventory of raw materials part & end
products.
• Less special machinery
• Products can be delivered in time.
• Reduction in selling price of the product & hence market is
expanded.
• It enables purchase of raw materials, interchangeable parts &
components from ready stock in the market without delay
• It leads to higher productivity in every department, which means
reduced cost.
• It enables good training of staff & workers.
BENEFITS TO CUSTOMERS
• Better quality of products & services.
• Cheaper products.
• Prompt delivery of products.
• Cheaper maintenance & repair of the products.
BENEFITS TO THE SELL OF GOODS
• Increased sales.
• Less amount invested on stocks.
• Sales promotion activities on fewer items.
• Less storage space is sufficient.
• Less overheads, handling charges and office work.
STANDARDS OF MEASUREMENTS
• Metrology is the science of measurements & the important
parameter is length.
• The various standards of linear measurements are:
• Line standard
• End standard
• Wave length standard
LINE STANDARD
Yard or meter is defined as the Distance between two marked lines on a
metal bar under Certain conditions of temperature and support.
• 1 yard = 0.91439841 meter.
• Bronze bar 1”x1” cross section & 38 ” length.
• Recess of dia 1” on both sides one inch away from the ends.
• A plug of gold materials having three lines marked transversely & two
lines longitudinally is inserted in to the recess.
• yard is defined as the distance between two central transverse lines at
62°f.
• This standard was legalized in 1853
LINE STANDARD - YARD
LINE STANDARD – METER
This standard was established originally by international bureau of weights &
measures in 1875. The prototype meter is made of platinum iridium alloy(90%
platinum & 10% iridium) having a cross section as shown in fig 1.13. the upper surface
of the web is highly polished and has 2 fine lines engraved over it. It is in oxidisable
and can have a good finish required for ruling good quality lines. The bar is kept at 0 c
and under normal atmospheric pressure
• LINE STANDARD – METER
• This standard was established originally by international
bureau of weights & measures in 1875.
• The prototype meter is made of platinum iridium alloy(90%
platinum & 10% iridium) having a cross section as shown in
fig.
• The upper surface of the web is highly polished and has 2
fine lines engraved over it.
• It is in oxidisable and can have a good finish required for
ruling good quality lines. The bar is kept at 0 c and under
normal atmospheric pressure
