An Overview on METROLOGY LABORATORY Venue : Training Hall Date :

An Overview on METROLOGY LABORATORY Venue : Training Hall Date :.

1. INTRODUCTION. Origin of Metrology: The word Metrology actually derives from the Greek words “METRON” and “LOGOS” which translated means the “Study of Measurement”. In modern world, the study of measurement is a vital component in many fields including manufacturing, engineering, science and technology. Within these fields, metrology is used to validate and verify to pre-defined standards. These standards are the bedrock of metrology and such are tested and verified against a recognised quality system by certified laboratories. Metrology splits into 3 subfields as follows. Scientific Metrology : which is also known as Fundamental metrology, covers the establishment of units of measure, units system and quantity systems. Industrial Metrology : which also refered to as Applied metrology, covers the calibration, maintenance and quality control of measuring instruments used in industries. Legal Metrology : It is the branch that looks after the regulatory aspects of measurements and measuring instruments..

1.1 DEFINITION. What is Metrology: Metrology is the science of Measurement . Metrology is not just about the routine making of measurements, its about the infrastructure that ensures that we have confidence in the accuracy of the measurements. It establish a common understeanding of units and measurements processes. Metrology covers the accuracy, precision, and repeatability of a measurement. It involves traceability or comparison with a 'standard' or between different measuring systems. Metrology includes all theoretical and practical aspects of measurement, whatever the measurement uncertainity or the field of application..

2. INSTRUMENTS USED FOR MEASUREMENTS.. Measurements: Measurements refers to the comparison of an unknown quantity or value with a known quantity or value. Measuring Instruments: The below tabulated were the measuring instruments used in Industries for measurements. Vernier Caliper Micrometer Height gauges Dial Indicators Basic Shop Floor Gauges.

2.1. VERNIER CALIPERS. INTRODUCTION TO VERNIER CALIPERS.

2.1. VERNIER CALIPERS. Caliper: A Caliper is a device used to measure the dimension of an object. Many types of calipers permit reading out a measurement on a ruled scale, a dial or a digital display. Vernier (Scale): A Vernier scale is named after “Pierre Vernier” - a French Mathematician in 1631, is a visual aid to take an accurate measurement readings between two graduation markings on a linear scale. Vernier Caliper: The Vernier Caliper is a precision measuring instrument used mainly for measuring linear dimensions accurately. It utilizes two graduated scales: One is like a simple ruler called main scale and the other one is called as vernier scale or auxillary scale. The vernier calipers have two jaws among which, one is fixed which is main scle and other is movable and is attached with vernier scale. The vernier scale enables us to take readings upto a fraction of divisions made on the main scale. This instrument is used to measure the outer dimensions of the object using main jaws, inner dimensions of the object using smaller jaws on the top and depth of the object using the depth bar or stem. Least Count: Least Count is defined as the smallest value, a measuring device can measure and it is also known as Vernier constant. Least count of an Analog Vernier Caliper is 0.02mm; Digital Vernier Caliper is 0.01mm ..

2.1. Nomenclature - ANALOG VERNIER CALIPERS. Vernier.

2.1.1. How to read a Vernier Scale - Analog Vernier..

2.1.1a How to read a Vernier Scale - Dial Vernier..

2.1.2. DIGITAL VERNIER CALIPERS.. Digi vernier.

Fig : 1 Fig : 3 Fig : 2. 2.1.3. Measuring Methodology..

2.1.4. Types of Vernier Calipers for various applications..

2.1.5. Points to be followed before using, while using and after using..

2.2 Micrometers.. INTRODUCTION TO MICROMETERS.. 1632898569385.

2.2 . Micrometers.. Origin: The word Micrometer is derived from the Greek words “Micros” and “Metron” which means 'small' and 'measure'. The first ever micrometric screw was invented by “William Gascoigne” in 17th century. Later the hand heldMicrometer was invented by “Jean Laurent Palmer” a French inventor in 1848. Micrometer: Micrometer is a also known as Screw Gauge, is a device used for taking an exact measurement of an object, used mainly by engineers. This handy instruments were sometimes used along with scientific devices such as microscopes and telescope to measure smaller objects. The Micrometers were classified into 3 types Outside Micrometer Inside Micrometer Depth Micrometer Least Count: Least Count is defined as the smallest value, a measuring device, Least count of the Micrometer is 0.01mm for an Analog Micrometer (Outside & Depth Micrometers), 0.005mm for Digital Micrometer (Inside Micrometers), 0.001mm for (Outside Micrometers).

2.2.1 Nomenclature - ANALOG OUTSIDE MICROMETER. Analog Micrometer.

Micrometer scale. 2.2.2. How to read the Micrometer..

2.2.2a. How to read the Micrometer.. Micrometer scale - micron.

2.2.3 DIGITAL MICROMETERS.. Digital Micrometer.

types of Mic - 1. 2.2.4. Micrometers for special applications..

2.2.5. Points to be followed before using, while using and after using..

2.3.0 HEIGHT GAUGE. INTRODUCTION TO HEIGHT GAUGES.

2.3.0. HEIGHT GAUGE. Introduction: Height gauges are precision measuring instrument which is mainly used to determine the height of an object or workpiece with high precision and accuracy, or to provide marked locations on the object relative to a reference plane. Height gauges were classified into three types Analog Height Gauge Digital Counter Height Gauge Electronic or Digital Height Gauge Years passes by, emerging of 2D Digital Height Gauges started to step in industries, which provides the results directly with highest accuracy and reliability..

2.3.1. Nomenclature - ANALOG HEIGHT GAUGE. Analog Height gauge : Height gauges consist of a sliding carriage with a moving scriber that is mounted to a vertical beam or column that contains a measuring scale (main scale), the scriber is attached with slider which can be moved vertically to measure an object. Least Count: Least count of the Analog Height gauge is 0.02mm..

2.3.2. Nomenclature - DIGITAL COUNTER HEIGHT GAUGE.

2.3.3. Nomenclature - DIGITAL HEIGHT GAUGE. Digital Height gauge : Digital Height Gauges consist of a sliding carriage additionally with an encoder in it. This allows us to measure much faster than Analog and Digital Counter Height gauges with high accurancy by getting output directly. Least Count: Least count of the Analog Height gauge is 0.01mm..

Additi onal probe holder and probe weight balance. Easy balance ac5ustment system- Interchangeable probe Functions button and air cushions button. Cast iron base for optimal stability. touch display with Intutive Functions. 33.0177 • 151N33 Horizontal Displacement handwheel m easuring carriage. manual or motorised.

2.3.5. Points to be followed before using, while using and after using..

INTRODUCTION TO DIAL & DIAL TEST INDICATORS. 2.4.0 DIAL INDICATORS.

2.4.1. Nomenclature - DIAL INDICATOR. Dial Indicator: The Dial Indicator provides a dial display similar to a clock face with pointer. The pointer points the graduations on the circular scales in the dial indicator which represents the distance measured. The Inner scale represents the range and the outer scale represents the resolution of the Dial Indicator. Least Count: Least count of the Dial Indicator is generaly 0.01mm, for special purposes 0.001mm; 0.002mm; 0.005mm least count dial indicators were used..

2.4.2. DIGITAL DIAL INDICATOR. Digital Dial Indicator: The Digital Dial Indicator is similar to the dial indicator in shape but no graduation scales or pointer in it, rather it has a digital display and linear encoder in it. The advantage of this digital dial indicator is, units can be switched to metric and inch, data can be transmitted, reduction of operator fatigue. Least Count: Least count of the Digital Dial Indicator is 0.001mm..

2.4.3. Nomenclature - DIAL TEST INDICATOR. Dial Indicator: The Dial Test Indicator which is also known as Lever Dial or Puppy Dial has a smaller measuring range than a standard dial indicator. A test indicator measures the deflection of the arm. The lever may be interchanged for length or ball diameter and permits measurement to be taken in narrow grooves and small bores. Least Count: Least count of the Dial Test Indicator is generally 0.01mm, for special purposes 0.001mm; 0.002mm; 0.005mm least count dial test indicators were used..

INTRODUCTION TO SHOP FLOOR GAUGES. 2.5.0 BASIC SHOP FLOOR GAUGE.

Plain Plug Gauges: Plain Plug gauges were basically used in shopfloor for checking plain tolerated holes. Plain Ring Gauges: Plain Ring gauges are used to check outside diameters of parts, and mainly used to set bore gauges, air gauges & internal micrometers. Thread Ring Gauges: Thread ring gauges are used for inspecting external screw threads of manufactured parts. With Go/NoGo thread ring gauges, an inspector can quickly pass or fail parts without taking time consuming readings from a measuring instrument. Thread Plug Gauges: Thread plug gauges are used to check the tolerances of threaded parts according to a certain specification. These highly specific calibration tools are used to assure the assembly of mating parts. Snap Gauges: A snap gauge is a form of go/no go gauge. It is a limit gauge with permanently or temporarily fixed measurement aperture which is used to quickly verify whether an outside dimension of a part matches a preset dimension or falls within predefined tolerances. Feeler Gauges: A feeler gauge is a tool used for measuring gaps or widths between two objects that are close together..